Slovakian Iced Chocolate Sandwich Cookies

Method

1. Preheat oven to 350°F (175°C).
2. In a bowl, whisk together flour, cocoa powder, baking powder, and salt.
3. In another bowl, cream together butter and sugar until fluffy.
4. Beat in egg and vanilla extract.
5. Gradually add dry ingredients to wet ingredients, mixing until a dough forms.
6. Roll dough into 1-inch balls and place on parchment paper-lined baking sheets.
7. Bake for 8-10 minutes until cookies are set but still soft.
8. Let cool completely before icing.
9. In a small bowl, mix confectioners' sugar and milk to create a thick icing.
10. Add food coloring if desired and stir until smooth.
11. Pipe or spread icing onto half of the cookies and sandwich with the other half.