Prepare the Chocolate Cookies:

• Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.

• In a small bowl, whisk together the flour, espresso powder, baking powder, and salt. Set aside.

• In a heatproof bowl, melt the semi-sweet baking chips and unsweetened baking chocolate together over a double boiler or in the microwave, stirring until smooth. Let cool slightly.

• In a separate large bowl, beat the butter and sugar together until light and fluffy, about 3 minutes.

• Add the eggs, one at a time, beating well after each addition. Stir in the vanilla extract.

• Gradually add the dry ingredients to the wet ingredients, mixing until fully combined. Then fold in the melted chocolate mixture.

• Drop spoonfuls of dough onto the prepared baking sheets, spacing them about 2 inches apart. Flatten each cookie slightly with the back of a spoon.

• Bake for 10-12 minutes, or until the cookies are set but still soft in the center. Allow the cookies to cool on the baking sheets for a few minutes before transferring them to wire racks to cool completely.

Make the Tiramisu Cream Filling:

• In a small bowl, dissolve the espresso powder in the warm coffee. Let cool to room temperature.

• In a medium bowl, beat the softened butter and sifted confectioners’ sugar together until smooth and creamy.

• Add the mascarpone cheese and continue to beat until fully incorporated.

• Gradually mix in the espresso-coffee mixture until the filling is smooth and fluffy.

Assemble the Cookies:

• Once the cookies have cooled, spread a generous amount of tiramisu cream filling on the flat side of one cookie.

• Top with another cookie, pressing gently to create a sandwich. Repeat with the remaining cookies and filling.