Begin by melting your butter in a saucepan over low heat, then let it cool slightly. In a mixing bowl, combine the melted butter with granulated sugar until smooth. Add in an egg and vanilla extract, stirring until fully combined. Gradually fold in flour, baking powder, baking soda, matcha powder, and salt until a cohesive dough forms.

Using a cookie scoop, portion the dough into uniform balls on a parchment-lined baking sheet. Gently flatten each ball and chill the baking sheet in the refrigerator for about 30 minutes.

While the dough chills, preheat your oven to 180ºC (355ºF). Prepare another baking sheet with parchment paper.

Place the chilled cookie dough onto the prepared baking sheet and bake for 10-11 minutes. They should be soft to the touch and slightly golden around the edges. Let cool on the tray for about 3 minutes before transferring to a wire rack.

In a mixing bowl, combine mascarpone cheese, confectioners sugar, agave or honey, and heavy cream. Whip on medium speed until stiff peaks form, then chill until ready to assemble the cookies.

Pipe the whipped mascarpone cream onto each cooled cookie and dust lightly with matcha powder.