01 -
Line two baking sheets with parchment paper and set aside.
02 -
In a medium bowl, whisk together flour, cocoa powder, salt, and baking powder until thoroughly combined.
03 -
In a large mixing bowl, cream together softened butter, light brown sugar, and granulated white sugar with an electric mixer for two minutes.
04 -
Add the egg yolks and vanilla to the butter-sugar mixture and mix until pale and fluffy, about 1–2 minutes.
05 -
Add the dry ingredients to the wet mixture and blend just until incorporated, avoiding overmixing.
06 -
Divide the dough into 34 equal portions, approximately 1 tablespoon each, and roll into balls.
07 -
Place dough balls onto the prepared baking sheets and press the center of each ball with a 0.25 tsp measure to create an indent.
08 -
Chill the indented dough balls in the refrigerator for at least one hour.
09 -
Preheat the oven to 175°C (350°F).
10 -
Arrange chilled dough balls 4 cm apart on baking sheets, then bake for 9–11 minutes. Remove from oven and immediately reinforce the indents using the 0.25 tsp measure. To achieve a uniform circular shape, gently run a round cookie cutter around each cookie while hot.
11 -
Allow cookies to cool on baking sheets for 5 minutes, then transfer to a wire rack to cool completely.
12 -
Place chocolate chips in a heatproof bowl. Heat heavy whipping cream until just below boiling, then pour over chocolate. Let stand for 1 minute, then stir until smooth and combined.
13 -
Spoon approximately 1 tsp ganache into each cookie center. Top with nonpareils if desired.
14 -
Chill the filled cookies in the refrigerator for 10–15 minutes to allow the ganache to firm.
15 -
Store cooled cookies in an airtight container for up to three days.