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

In a medium bowl, whisk together the flour, espresso powder, baking powder, baking soda, and salt until well combined.

In a separate large bowl, beat the softened butter until creamy, then gradually add the granulated and brown sugars, mixing until light and fluffy.

Add the room temperature egg and vanilla extract to the butter-sugar mixture, mixing until fully incorporated.

Slowly add the dry ingredient mixture to the wet ingredients, folding gently until just combined.

Use a cookie scoop to portion out the dough onto the prepared baking sheet, spacing them 2 inches apart.

Bake for 11-12 minutes, or until the edges are set and the centers look soft.

Cool on the baking sheet for about 5 minutes before transferring to a wire rack.

Beat the mascarpone cheese in a bowl until creamy, then mix in the whipped cream, powdered sugar, and vanilla extract until just thickened.

Dollop or pipe the mascarpone cream onto each cookie and dust the tops with cocoa powder.