Preheat the oven to 350°F (175°C). Line a cupcake tin with cupcake liners.

In a large mixing bowl, whisk together the gluten-free flour, sugar, cocoa powder, baking powder, baking soda, and salt.

In another bowl, beat the eggs, milk, vegetable oil, and vanilla extract until well combined.

Gradually add the wet ingredients to the dry ingredients, mixing until just combined. Fold in the crushed chocolate cookies.

Divide the batter evenly among the cupcake liners, filling each about 2/3 full.

Bake for 18-20 minutes or until a toothpick inserted into the center comes out clean. Let cool in the pan for 5 minutes before transferring to a cooling rack.

In a mixing bowl, beat the softened butter until creamy.

Gradually add the powdered sugar, beating until smooth.

Add the heavy cream and vanilla extract, and continue to beat until the frosting is light and fluffy.

Once the cupcakes are completely cooled, frost them generously with the prepared frosting.

Sprinkle the crushed chocolate cookies on top of the frosted cupcakes.