Chocolate Sandwich Cookies

Whisk together the flour, cocoa powder, baking soda, and salt in a small bowl.

Beat the butter and sugar in a mixer bowl until light and fluffy.

Add the egg and vanilla extract, beating until smooth.

Gradually add the flour mixture while continuing to beat until a uniform dough forms.

Cover the bowl of dough and refrigerate for 20 minutes.

Preheat the oven to 160°C (325°F). Line 3 baking sheets with parchment paper.

Drop the dough onto the baking sheets in equal small portions. Press down with the palm of your hand to a thickness of 5-6 mm.

Bake for 15-17 minutes until the cookies are set and matte in appearance.

Remove from the oven and let cool on the baking sheets for 5 minutes. Transfer to a wire rack to cool completely.

Beat the butter, sugar, vanilla extract, and mint extract in a mixer bowl until thick and smooth for the filling.

Turn half of the cookies over and place a dollop of filling on the bottom side.

Top with the remaining cookies and press down slightly so the filling spreads evenly.

Place the filled cookies on a baking sheet and refrigerate.

Place the chocolate chips in a bowl with the vegetable oil and melt in the microwave in 30-second intervals, removing and stirring until smooth.

Remove the cookies from the refrigerator, drizzle with chocolate, smoothing the surface with the back of a spoon.