01 - 
                Melt the butter in the microwave or a small saucepan over low-medium heat, avoiding bubbling to prevent liquid loss. Pour into a large mixing bowl and cool to room temperature in the fridge, about 20 minutes.
              
              
              
                02 - 
                Add granulated sugar and brown sugar to the cooled butter. Mix with a spatula or a stand mixer on medium speed for 1 minute.
              
              
              
                03 - 
                Mix in the egg and vanilla extract until fully combined.
              
              
              
                04 - 
                In a separate bowl, combine flour, baking powder, baking soda, espresso powder, and salt. Gradually add the dry mixture to the wet ingredients, mixing until just combined.
              
              
              
                05 - 
                Using a 2-tablespoon cookie scoop, form 11 cookie portions. Roll each into a smooth ball and place on a baking tray lined with baking paper. Refrigerate for 1 hour.
              
              
              
                06 - 
                Preheat the oven to 180ºC (355ºF) and prepare a baking sheet with baking paper.
              
              
              
                07 - 
                Place six cookies per baking tray and bake one tray at a time for 10-11 minutes. Let cool on the tray for 3 minutes before transferring to a cooling rack.
              
              
              
                08 - 
                Whip mascarpone cheese, vanilla extract, confectioners sugar, agave, and heavy cream using an electric mixer or stand mixer with a whisk attachment until stiff peaks form. Refrigerate if preparing ahead.
              
              
              
                09 - 
                Transfer mascarpone cream to a piping bag with a Wilton 2A tip. Pipe cream in a swirl pattern onto cooled cookies. Dust with cocoa powder before serving.