Preheat oven to 350 F. Place ice cream cones in a baking dish. In a large bowl, whisk together flour, sugar, cocoa powder, salt, baking powder, and baking soda. Add in eggs, milk, oil, and vanilla extract. Whisk until smooth.
Evenly divide the batter between ice cream cones. Bake for 20-25 minutes. Let cool completely.
In a large bowl with a mixer, beat butter with powdered sugar, milk, and vanilla extract until smooth. Pipe frosting onto cupcakes.