Combine softened butter and sugar in a large bowl (or the bowl of a stand mixer fitted with a paddle attachment) and use an electric mixer to beat until creamy and well-combined.

Add egg and vanilla extract and use mixer to stir until thoroughly combined.

In a separate bowl, whisk together flour, baking powder, and salt.

With mixer on low-speed gradually stir flour mixture into butter mixture (I like to do this in 4-5 parts, don’t add it all too quickly or the dough could become dry and difficult to manage). Scrape the sides and bottom of the bowl periodically to ensure all ingredients are well-combined and no flour remains.

Divide dough into two equal parts and form each into a disk. Wrap each in plastic wrap and refrigerate for at least 3 hours or overnight.

Shortly before removing dough from refrigerator, preheat oven to 350F (175C) and line a baking sheet with parchment paper (if you don’t have parchment, bake cookies directly on an ungreased baking sheet).

Once dough has chilled, remove from refrigerator and unwrap. Place on a lightly floured surface and dust dough with flour. Use a rolling pin to roll to just under ¼” (0.6cm) thick. Note: If dough chilled longer than 3 hours and/or is too cold/firm to roll and starts to crack, let it sit at room temperature for 15-20 minutes before attempting to roll again. It often helps to use a spatula to scrape up the bottom of the dough to make sure it isn’t sticking to the counter as you roll it, this will make it easier to lift the cookies, as well!

Use bunny cookie cutter to cut out cookies as close together as possible and use a spatula to lift them to a parchment paper lined baking sheet, spacing cookies at least 2” apart.

Transfer to 350F (175C) preheated oven and bake for 10-12 minutes or until edges are beginning to turn light golden brown. Allow cookies to cool on baking sheet for at least 5 minutes before using a spatula to transfer them to baking sheet to cool completely. While cookies are cooling, prepare frosting.

In a large bowl, whisk together powdered sugar, 3 Tablespoons milk, corn syrup, and vanilla extract until mixture is smooth. Add milk as needed until you have a smooth consistency where, when the whisk is lifted from the frosting, the frosting falls in a ribbon back into the bowl and holds its shape for several seconds before dissolving back into the mixture. Note: if you accidentally make the frosting too thin, simply add more sugar.

Measure out ¼ cup of frosting into a separate dish and stir in brown food coloring until you have an even dark brown color. Transfer to a piping bag fitted with a Wilton #3 tip (or similar). Transfer the remaining white frosting to a piping bag fitted with a Wilton #5 tip (or similar). Divide your sanding sugar into separate, shallow dishes that your cookies will fit into. Do not ice cookies until they have cooled completely.

Work with one cookie at a time. Use the white frosting to pipe an outline near the edge of each sugar cookie (do not go all the way to the edge of the cookie or it will get messy!). Immediately fill the outline with white frosting and use a decorator tool or toothpick to smooth the frosting and fill any gaps (see collage in post or video for a visual).

Immediately, gently, place cookie frosting-side down in one dish of sanding sugar. Gently shake the dish to ensure all of the frosting is covered in sugar. Carefully lift the cookie and gently tap to shake off excess sugar.

Place cookies sugar-side up on rack and use brown frosting to pipe eyes and a nose on your bunnies.

Allow frosting to set completely before enjoying (this may take several hours, I usually let mine sit out overnight).