In a large mixing bowl, whisk together all-purpose flour, granulated sugar, baking powder, and salt.

In a separate bowl, cream the unsalted butter until smooth and fluffy, then add large eggs and espresso powder, mixing until fully incorporated.

Chill the dough in the refrigerator for 30 minutes.

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

Scoop out about 1-inch portions of dough, roll into balls, and coat in powdered sugar.

Arrange on the prepared baking sheet, spacing them about 2 inches apart.

Bake for 10-12 minutes until golden around the edges, keeping centers soft.

Create indents in the center of each cookie while still warm.

Whip mascarpone cheese and heavy cream together until glossy and thick.

Fill indents in each cookie with the mascarpone mixture.

Chill the filled cookies for 15-20 minutes for optimal flavor.