Prepare the Dough:

• Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.
• In a medium bowl, whisk together the flour, cocoa powder, baking powder, and sea salt.
• In a separate large bowl, cream the softened butter, brown sugar, and granulated sugar until light and fluffy (about 2 minutes).
• Beat in the egg yolks and vanilla extract, mixing until well combined.

Combine and Form the Cookies:

• Gradually add the dry ingredients to the wet mixture, mixing just until a soft dough forms.
• Roll the dough into 1-inch balls and place them on the prepared baking sheets, spacing them about 2 inches apart.

Make Thumbprints:

• Using your thumb or the back of a spoon, press a small indentation into the center of each dough ball.

Bake the Cookies:

• Bake in the preheated oven for 8–10 minutes, or until the edges are set but the centers remain soft.
• Remove from the oven and gently repress the indentations if needed. Let the cookies cool completely on a wire rack.

Prepare the Ganache Filling:

• In a small saucepan, heat the heavy cream until it just begins to simmer.
• Pour the hot cream over the chopped chocolate in a heatproof bowl. Let it sit for 1–2 minutes, then stir until smooth and glossy.

Assemble the Cookies:

• Spoon a small amount of cherry preserves into the indentation of each cooled cookie.
• Drizzle or pipe the chocolate ganache over the cherry preserves.

Set and Serve:

• Let the cookies sit at room temperature until the ganache is set. Serve and enjoy!