Start with your prepared sugar cookie dough and chill it for 20 minutes to make it easier to work with and roll out. This resting period helps the gluten relax and prevents the dough from shrinking too much during baking. While the dough chills, preheat your oven to 350°F so it will be ready when you need it.
On a floured work surface, roll out the chilled dough to 1/8 to 1/4 inch thickness—thinner cookies will be crispier, while thicker ones will be softer, so choose based on your preference. Using an egg-shaped cookie cutter, cut out shapes and place them about 1 inch apart on parchment-lined baking sheets. Once shaped, chill the cookie cutouts for 30 minutes in the refrigerator to prevent them from spreading too much during baking.
Bake the chilled cookies one baking sheet at a time for about 12 minutes at 350°F, until the edges are just barely golden but the centers are still soft. I always rotate the pan halfway through to ensure even browning, especially if your oven has hot spots. Once baked, transfer the cookies to a wire rack and let them cool completely—this is important because warm cookies are too delicate to frost.
While the cookies cool, prepare your buttercream frosting and tint it with food coloring if desired to match your Easter theme. In a small bowl, whisk together the vanilla extract and cocoa powder until smooth and well combined—this creates a paint-like consistency that will stick to the frosting without dripping. I find that mixing these together beforehand prevents lumpy cocoa specks from appearing on the finished cookies.
Once the cookies are completely cool, spread a thin to medium layer of buttercream frosting on each egg-shaped cookie using an offset spatula or butter knife. Using a small brush or flick technique, apply the cocoa-vanilla mixture across the frosted surface to create speckled detail that mimics real Easter eggs. Immediately top each cookie with a few crushed mini candy eggs, pressing them gently into the frosting so they adhere. The frosting sets slightly as it sits, so work efficiently but don't rush—taking your time creates a more polished presentation.