Easy Tiramisu Cookies with Mascarpone Frosting

0 Preheat your oven to 350°F (180°C) and line two baking trays with parchment paper. This prevents sticking and helps the cookies bake evenly.
1 In the bowl of a stand mixer fitted with the paddle attachment, cream softened butter and sugar together on medium speed until light and fluffy. Scrape down the sides of the bowl with a rubber spatula to make sure everything is well mixed. 
2 Add the vanilla extract, then beat in the large egg and yolk until smooth.
3 In a separate bowl, whisk together the dry ingredients: all-purpose flour, instant espresso powder, baking powder, baking soda, and salt. Slowly add these dry ingredients to the wet mixture on low speed, mixing until just combined. Be careful not to add too much flour or overmix, as this can make the cookies dense.
4 Scoop cookie dough balls using a cookie scoop (about 3 tablespoons each). If the dough feels sticky, chill it in a small bowl for 15 minutes. Place them on the prepared baking sheet, spaced 2 ½ inches apart.
5 Bake in the lower third of the oven for 10-15 min, until the edges of the cookies are set, but the centers still look slightly soft. Transfer baked cookies to a wire rack or cooling rack after 5 minutes to cool completely.
6 Beat mascarpone cheese, powdered sugar, vanilla extract, and optional instant coffee in a medium bowl with an electric mixer or hand mixer. 
7 In a separate bowl, whip the heavy cream with the whisk attachment until medium to stiff peaks form. Gently fold the whipped cream into the mascarpone mixture with a rubber spatula until smooth.
8 Spread the creamy mascarpone frosting generously over the cooled cookies using a small offset spatula or pipe using an 1M piping tip. Finish with a dusting of cocoa powder in a circular motion for the perfect tiramisu cookie recipe presentation.