Begin by preheating your oven to 350°F (175°C) and lining two baking sheets with parchment paper.

In a medium bowl, whisk together 1 ¾ cups of all-purpose flour, ½ cup of Dutch process cocoa powder, ½ teaspoon of salt, and ½ teaspoon of baking powder.

In a large mixing bowl, cream together ¾ cup of softened unsalted butter, ½ cup of light brown sugar, and ¼ cup of granulated sugar.

Next, add 2 egg yolks and 1 teaspoon of vanilla bean paste or extract to the butter-sugar mixture.

Gradually add the dry ingredients to the wet mixture, stirring until just combined.

Using a cookie scoop or tablespoon, scoop the dough into approximately 34 portions, roll into balls, and place on the prepared baking sheets.

Refrigerate the indented dough balls for at least 1 hour.

After chilling, bake for 9 to 11 minutes, keeping an eye on them.

Let the cookies cool on the baking sheets for about 5 minutes before transferring to a wire rack.

For the ganache, heat 1/3 cup of heavy whipping cream in a saucepan until boiling, then pour over 6 ounces of semi-sweet chocolate chips and stir until smooth.

Once the cookies are cool, fill each indent with about 1 teaspoon of ganache.

Chill the filled cookies in the refrigerator for 10 to 15 minutes to set the ganache.