This batch of chocolate hazelnut thumbprint cookies has been my favorite small celebration treat for years, the kind I make when friends stop by unexpectedly or when I want to brighten a rainy afternoon. I discovered this combination while trying to adapt a classic shortbread thumbprint into something richer and more adult friendly. The cocoa in the dough gives a deep chocolate backbone, the chopped hazelnut coating adds crunch and aroma, and the warm Nutella ganache tucked into the centers creates a creamy, irresistible finish. Every time I take them out of the oven the kitchen fills with a toasted nut and chocolate perfume, and my family gathers around the cooling rack to steal one or two while they are still warm. I love how the texture balances. The edges set with a slight chew while the center stays tender, and the nut crust provides a textural contrast that makes each bite interesting. This is not a sickly sweet cookie. The brown sugar and a touch of granulated sugar lend caramel notes and a fine but crisp exterior. I often bring these to weekend brunches and they disappear first. You will find the technique forgiving, and with an overnight chill the flavors deepen and the dough is easier to handle. This version uses simple pantry staples and two ingredients for the filling, making it a perfect candidate for an afternoon bake session that yields beautiful results and keeps well for gifting.

Ingredients

• All purpose flour 1 1/2 cups, spooned and leveled. Use a soft wheat all purpose flour such as King Arthur for reliable structure. Measure by spooning into the cup to avoid packing which makes dense cookies.
• Cocoa powder 1/2 cup unsweetened. I like Dutch process for a deeper chocolate color and a milder acidity. Sift to remove lumps for even distribution in the dough.
• Baking powder 1/2 teaspoon to give a modest lift so the centers stay tender while the edges set.
• Fine sea salt 1/4 teaspoon. Enhances the chocolate and balances the sweetness. If using table salt, reduce slightly.
• Unsalted butter 1/2 cup at room temperature. Use real butter such as Plugra or Kerrygold for flavor. Room temperature ensures smooth creaming with the sugars.
• Light brown sugar 1/4 cup and granulated sugar 1/2 cup. The brown sugar adds moisture and a caramel note while granulated sugar gives a clean sweetness and a slight crisp to the outer crumb.
• Large egg yolk 1 yolk only. The yolk adds richness without excess liquid which keeps the cookie tender.
• Vanilla extract 1 teaspoon for aromatic depth. Use pure vanilla when possible for a rounder flavor.
• Milk 1 tablespoon. Just enough to bring the dough together without making it sticky.
• Finely chopped hazelnuts 3/4 cup, toasted if possible. Toasting intensifies the nut aroma. Chop to a fine but not powdery texture so they adhere to the dough.
• Nutella 1/2 cup for the ganache filling. Use room temperature for easier melting into the cream.
• Heavy cream 1/4 cup to make the ganache. Heat until just simmering to melt the Nutella smoothly.

Instructions

Prepare dry ingredients In a medium bowl whisk together the flour, cocoa powder, baking powder, and salt. Whisk thoroughly so the cocoa is evenly distributed and there are no pockets of baking powder which can produce bitter metallic pockets. Set this bowl aside while you cream the butter and sugars. Cream butter and sugars In a large mixing bowl or stand mixer fitted with the paddle attachment beat the room temperature butter with the light brown sugar and granulated sugar on medium speed until light and fluffy, about 2 to 3 minutes. Scrape the bowl halfway through to ensure even aeration. You are looking for a pale, airy texture which helps the cookies spread minimally and remain tender. Add wet ingredients Add the egg yolk, vanilla, and milk, then beat until smooth. The mixture will look glossy and cohesive. If the mixture appears curdled gently continue mixing for a short time, it will come together once the flour is added. Incorporate dry ingredients With the mixer on its lowest speed add the flour mixture in two additions, mixing only until just combined. The dough will be crumbly at first. Use clean hands to press the bits together into a smooth ball. Avoid overworking which can develop gluten and make the cookies tough. Wrap the dough in plastic wrap and refrigerate at least one hour or overnight for better flavor and handling. Shape and chill When ready to bake let the dough sit 10 to 15 minutes at room temperature so it is scoopable. Portion about 1 tablespoon per cookie, roughly 20 grams, and roll into smooth balls. Roll each ball in the chopped hazelnuts to coat. Arrange on a parchment lined baking sheet two inches apart. Press an indentation into the center of each cookie with your thumb or the handle end of a wooden spoon to make a well for the filling. Refrigerate the shaped cookies for 30 minutes before baking to help them keep their shape. Bake Preheat the oven to 350 degrees Fahrenheit. Bake the chilled cookies for 10 to 12 minutes until the edges are set and the centers remain slightly soft. If the pressed wells puff up during baking gently re-press while the cookies are still warm. Allow them to cool on the baking sheet for 5 minutes then transfer to a wire rack to cool completely before filling. Make Nutella ganache Place the Nutella in a heatproof bowl. Heat the heavy cream in a small saucepan until it reaches a gentle simmer but does not boil. Pour the hot cream over the Nutella and let rest for 5 minutes. Stir until silky and smooth. The mixture will thicken as it cools to room temperature. Fill the centers Transfer the ganache into a piping bag and snip the tip. Pipe a small mound of ganache into each cooled cookie well. Let set at room temperature until the ganache firms slightly. Store in an airtight container for up to three days at room temperature or up to one week refrigerated.

Storage Tips

Store the cookies in a single layer in an airtight container at room temperature for up to three days. If you want them to remain soft place a slice of apple or a piece of bread in the container to preserve moisture for a day or two. For longer storage place unfilled baked cookies in a freezer safe bag and freeze for up to three months. Thaw at room temperature and fill with room temperature ganache for best mouthfeel. Avoid stacking filled cookies until the ganache has fully set to prevent sticking and cosmetic damage.

Ingredient Substitutions

If you need a dairy free option replace the butter with a plant based block butter and use a non dairy cream alternative that heats without separating for the ganache. For a gluten free version swap the all purpose flour for a 1 to 1 gluten free blend and add 1/4 teaspoon xanthan gum if your blend lacks it to improve structure. To vary the nuts use finely chopped almonds or pistachios which will change the aroma but still give a pleasant crunch. If you prefer a more intense chocolate center use a 50 50 blend of Nutella and melted dark chocolate for a firmer filling.

Serving Suggestions

Serve these with espresso or roasted tea for an elegant afternoon pairing. They are lovely plated on a small dessert tray with fresh berries and a dusting of cocoa. For gift tins stack with parchment between layers and include a small jar of extra ganache for topping. They work well at brunch or as part of a cookie assortment for celebrations.

Cultural Background

Thumbprint cookies trace their roots to central European baking where small buttery cookies often held jam or chocolate in the center. This version blends that tradition with Italian inspired gianduja flavors by using hazelnuts and Nutella. The combination recalls classic pairings such as hazelnut spread on biscotti and has become popular in contemporary home baking for its nostalgic feel and crowd pleasing flavors.

Seasonal Adaptations

For colder months incorporate warm spices like 1/4 teaspoon cinnamon or a pinch of instant espresso powder in the dough to deepen the chocolate notes. For spring or summer swap part of the ganache for a raspberry jam swirl to add brightness. Add a sprinkle of flaky sea salt to the centers for a festive contrast around the holidays.

Meal Prep Tips

Make the dough and chill it overnight to save time the next day. Shape and roll in chopped hazelnuts then freeze the shaped balls on a tray until firm. Transfer to a bag and bake straight from frozen, adding 1 to 2 minutes to the bake time. The ganache can be made ahead and warmed gently before piping. Pack in small airtight containers for grab and go treats.

These cookies are simple to adapt and a joy to share. Make a batch for a neighbor and enjoy seeing how quickly they vanish from the plate.