In a large mixing bowl, cream together softened butter and sugar until light and fluffy, about 3-5 minutes. Gradually add vanilla extract, followed by egg, mixing until combined. Slowly incorporate flour and a pinch of salt until a soft dough forms. Wrap the dough in plastic wrap and refrigerate for 20 minutes.

Lightly flour a clean surface and roll out the chilled dough to about 1/8 to 1/4 inch thick. Use egg-shaped cookie cutters to create your Easter Egg Sugar Cookies, placing them carefully onto a lined baking sheet.

Once all cookies are cut out, place the baking sheets in the refrigerator for 30 minutes.

After chilling, bake the cookies in your preheated oven for approximately 12 minutes or until the edges are just golden and the centers are set.

While the cookies cool, prepare your buttercream by beating together softened butter and powdered sugar until smooth. Add vanilla extract and gel food coloring to achieve your desired color.

Once the cookies are completely cooled, generously frost each one with buttercream. Mix cocoa powder with a little water and splatter over cookies for a speckled effect, and top with crushed Cadbury mini eggs.