01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners.
02 - Sift together flour, cocoa powder, baking powder, baking soda, and salt in a medium bowl.
03 - Whisk eggs and sugar in a large bowl until light and fluffy. Blend in milk, vegetable oil, and vanilla extract until combined.
04 - Gradually add dry ingredients to wet mixture, stirring until just incorporated. Do not overmix.
05 - Divide batter evenly among cupcake liners. Bake for 16-18 minutes until a toothpick inserted in center comes out clean. Cool completely.
06 - Beat butter until creamy. Mix in powdered sugar and cocoa powder. Add vanilla and 2 tbsp milk; beat until fluffy, adding more milk if needed for spreading consistency.
07 - Generously frost cooled cupcakes with chocolate frosting.
08 - Carefully twist Oreos apart, keeping cream on one side. Place two halves cream-side up on each cupcake as eyes.
09 - Press a brown candy on each eye for pupils. Position an orange or yellow candy below the eyes as the beak. Use Oreo halves without cream on top corners as eyebrows if desired.