Preheat your oven to 350°F (175°C). Spread the hazelnuts on a baking sheet and toast them for 10-12 minutes, or until they’re fragrant and lightly golden. Let them cool before chopping coarsely.

In a mixing bowl, whisk together the flour, cocoa powder, baking powder, and salt until well combined. Set aside.

Cream the butter with granulated and brown sugars for about 2-3 minutes until light and fluffy.

Add in the egg and vanilla extract, blending until fully combined and scraping the bowl.

Gradually add the dry mixture to the wet ingredients, mixing on low speed until just combined. Fold in the toasted hazelnuts carefully.

Scoop dough portions, roll into balls and place on a lined baking sheet, flattening them slightly.

Bake the cookies for 10-12 minutes until edges are set with soft centers. Cool on the sheet for a few minutes before transferring to a wire rack.

Melt the chocolate in a microwave-safe bowl, stirring every 30 seconds until fully melted. Dip half of each cookie in the melted chocolate.

Let the chocolate coating set at room temperature for 15-30 minutes.