Melt the butter in the microwave or in a small saucepan over low-medium heat. Pour the melted butter into a big mixing bowl and let it cool down to room temperature in the fridge. Takes about 20 minutes.

Once the butter has reached room temperature, add the granulated sugar and brown sugar, and whisk it together for 1 minute.

Add the egg and vanilla extract and mix it in until combined.

In a separate bowl, stir together flour, baking powder, baking soda, instant espresso powder, and salt. Add the dry ingredients to the wet mixture and mix until just combined.

Using a 2 tbsp/1.3 ounce cookie scoop, scoop out 11 cookies and roll them between your hands into a ball. Place in the fridge to set for 1 hour.

Preheat the oven at 180ºC/355ºF and prepare a baking sheet with baking paper. Bake one tray at a time for 10-11 minutes.

Let cookies cool down on the baking tray for 3 minutes, then lift them onto a cooling rack to cool completely.

In a medium bowl with an electric mixer, whip together all of the mascarpone cream ingredients until it reaches stiff peaks. Refrigerate if making ahead.

When ready to serve, pipe the mascarpone cream on top of the cookies in a swirl, dust with cocoa powder.