Step 1: Make the Cookie Dough
In a large bowl, cream softened butter and sugar for 2–3 minutes until light and fluffy.
Add egg and vanilla extract. Mix until smooth.
In a separate bowl, whisk together flour, baking powder, and salt.
Gradually add dry ingredients to wet ingredients and mix just until combined.
Form dough into a disk, wrap, and chill for at least 1 hour.
Step 2: Roll & Bake
Preheat oven to 350°F (175°C).
Roll dough on a lightly floured surface to ¼-inch thickness.
Cut into circles or desired spring shapes.
Place on parchment-lined baking sheets.
Bake 8–10 minutes, until edges are lightly golden but centers remain pale.
Cool completely before filling.
Step 3: Make the Buttercream
Beat softened butter until smooth and creamy.
Gradually add powdered sugar, mixing well.
Add vanilla extract and milk until smooth and fluffy.
Divide into bowls and tint with pastel gel food coloring.
Step 4: Assemble the Sandwiches
Pipe or spread buttercream onto the flat side of one cookie.
Top with another cookie and gently press together.
Roll edges in pastel sprinkles if desired.