Hazelnut Chocolate Sandwich Cookies

There’s something irresistible about a cookie that’s crisp at the edges but stays soft and buttery in the center — and that’s exactly what these hazelnut chocolate cookies deliver. Made with toasted hazelnuts folded into rich butter dough, then sandwiched with melted dark chocolate, they’re ready in about 35 minutes. No fancy equipment needed, just a comforting homemade treat for coffee time.

How to Properly Prepare the Hazelnuts

Toasting and chopping the hazelnuts correctly is one of the most important steps in this recipe, since it directly affects both flavor and texture. Start by drying the hazelnuts — either in a dry skillet over low heat or in the oven — until their skins loosen and their aroma deepens, which brings out a richer, roasted flavor than raw nuts would give. Once cooled slightly, pulse them in a blender or food processor until finely ground, but be careful not to over-process into a paste; you want a fine, sandy texture that blends smoothly into the dough. If the hazelnuts are too coarse, the dough won’t hold together well when shaped into balls, and if they’re too fine, you lose the pleasant bite that makes these cookies special. Skinning the hazelnuts beforehand also prevents any bitterness from the papery skins from coming through in the final baked cookie.

The Right Way to Mix the Butter and Sugar

Creaming the butter with powdered sugar, vanilla sugar, and a pinch of salt is what gives these cookies their light, melt-in-your-mouth quality. Using softened — not melted — butter is essential, since melted butter causes the dough to spread too much during baking and results in flat, greasy cookies instead of neat rounds. Beat the mixture with a hand or stand mixer for a full two minutes until it turns pale and fluffy, which incorporates air and helps the finished cookie stay tender rather than dense. Powdered sugar, rather than granulated, is used specifically because it dissolves completely and doesn’t create a grainy texture in the baked dough. Once this base is properly whipped, the flour and ground hazelnuts fold in easily without overworking the dough, which keeps the cookies from turning tough after baking.

Shaping and Baking the Cookie Dough

After the flour and hazelnuts are folded into the butter mixture, the dough should be soft but firm enough to roll into small balls, roughly 7-8 grams each, about the size of a walnut. Keeping the balls uniform in size ensures they bake evenly, so all the cookies finish at the same time and end up with matching thickness for even sandwiching later. Arrange them with a little space between each on a parchment-lined baking sheet, since the dough will spread slightly as the butter melts in the oven. Bake in a preheated oven at 190°C (375°F) for 15-17 minutes, watching closely toward the end, since hazelnut-based dough can go from perfectly golden to overly dry very quickly. The goal is a light golden color on the edges while the tops remain just barely set.

Assembling the Sandwich Cookies

Once both the cookies and chocolate are ready, pair up the baked cookie halves by matching similar sizes so the finished sandwiches look neat and uniform. Spread or pipe a thin, even layer of melted chocolate onto the flat side of one cookie, then gently press the second cookie on top, being careful not to press so hard that the chocolate squeezes out the sides. Working in batches keeps the chocolate from cooling and hardening before you’ve finished assembling all the cookies. This step goes quickly once you get into a rhythm, and it’s the moment where the cookies transform from simple baked treats into the finished sandwich version.