Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a medium saucepan, melt the unsalted butter and semi-sweet chocolate chips over low heat, stirring frequently until smooth. Remove from heat and let cool for a few minutes.

In a large bowl, combine the granulated sugar and brown sugar. Pour the melted chocolate mixture into the sugars and stir until well combined.

Beat in the eggs, one at a time, mixing well after each addition. Then stir in the vanilla extract.

In another bowl, whisk together the flour, cocoa powder, baking powder, and salt. Gradually add this mixture to the wet ingredients, folding until just combined.

Gently fold in the chocolate hearts or chunks.

Using a cookie scoop, drop dough onto the prepared baking sheet, spacing them apart. Bake for 12-14 minutes, or until the edges are firm but the centers remain soft.

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