Preheat oven to 350°F. Prepare baking pans with cupcake liners.
Combine flour, sugar, cocoa powder, baking powder, baking soda, and salt in a stand mixer or large bowl.
Add eggs, one at a time. Stir in milk, oil, and vanilla until well combined.
Stir in boiling water and mix thoroughly.
Pour into baking pans, filling cups 3/4 full. Bake 22-25 minutes. Cool completely before decorating.