Preheat oven to 300°F and prepare a cupcake pan with liners. Combine dry ingredients in a large bowl.

In another bowl, whisk egg, milk, vegetable oil, and vanilla extract. Mix wet and dry ingredients until smooth.

Gradually add hot water to the batter, mixing until thin. Fill cupcake liners halfway and bake for 18-23 minutes. Cool completely.

Make vanilla buttercream by beating butter until creamy. Incorporate powdered sugar and vanilla, then add heavy cream until desired consistency is reached.

Divide buttercream. Tint a portion green with gel color, and mix remaining with cocoa powder for chocolate buttercream.

Frost cupcakes with chocolate buttercream using Wilton tip 21. Pipe green grass around each cupcake with Wilton tip 233.

Fit Wilton tip 3 with white buttercream and pipe laces on each football. Serve or store in an airtight container.