Ingredients
Method
- Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.
- Cream butter and sugar together until smooth.
- Mix in egg and vanilla extract.
- In another bowl, whisk flour, cocoa powder, baking soda, and salt.
- Add dry ingredients into wet mixture and mix until dough forms.
- Roll dough into small balls and flatten slightly onto baking sheets.
- Bake for 8–10 minutes until edges are set.
- Cool cookies completely on a wire rack.
- Beat butter for filling until creamy, then mix in powdered sugar and vanilla extract. Add milk if needed.
- Spread or pipe filling onto half the cookies and sandwich with remaining cookies.
Notes
Let cookies cool completely before filling or the filling will melt. For softer sandwich cookies, let them sit in a sealed container for a few hours before serving. Store in an airtight container for up to 5 days.
