Prepare the Dough: In a stand mixer, beat unsalted butter and full-fat cream cheese until smooth and creamy. Add granulated sugar, mixing until light and fluffy. Incorporate egg and extracts.

Combine Dry Ingredients: In a separate bowl, whisk together all-purpose flour, cornstarch, fine salt, and baking powder. Gradually mix into the wet mixture until just combined.

Chill the Dough: Divide the dough into two parts, wrap in plastic, and chill in the refrigerator for at least 1 hour.

Roll and Cut Shapes: Preheat oven to 350°F (175°C). Roll out chilled dough on floured surface to about 1/3 inch thick. Use a bunny cookie cutter to cut shapes.

Final Chill: Place cut-out cookies on baking sheet and chill in fridge for 15 minutes.

Bake the Cookies: Bake cookies for about 10 minutes until edges are set. Let cool on baking sheets for 15 minutes.

Prepare the Frosting: Beat unsalted butter until smooth. Gradually mix in powdered sugar and heavy whipping cream until desired consistency is reached.

Decorate the Cookies: Frost each cooled cookie with white buttercream, then use gel food coloring and black round sprinkles to pipe bunny faces.