Preheat oven to 300°F and prepare a cupcake pan with liners.

Combine flour, sugar, cocoa, baking soda, and salt in a large bowl.

Whisk egg, milk, oil, and vanilla in a medium bowl.

Mix wet ingredients into dry until well combined.

Add hot water and stir until smooth. Batter will be thin.

Fill liners halfway and bake for 18-23 minutes.

Cool cupcakes for 2 minutes, then transfer to a wire rack.

Beat butter until creamy. Add half of powdered sugar and mix.

Mix in vanilla, heavy cream, and salt until smooth.

Add remaining powdered sugar and beat to desired consistency.

Reserve ¼ cup vanilla buttercream for white icing. Color remaining green.

Add cocoa powder to remaining buttercream for the chocolate football frosting.

Pipe football shape onto cupcakes with Wilton tip 21.

Use green buttercream to pipe grass around footballs with Wilton tip 233.

Pipe white laces on footballs with Wilton tip 3.