0.25 cups of cocoa powder is equivalent to 4 tablespoons. It is about the size of a large egg when poured into a loose pile.

In kitchen measures
4 tablespoons
12 tsp · 4 tbsp · 0.25 cups
about the size of a large egg
Cocoa powder typically ranges 0.5–0.7 g/mL depending on how it's packed. A firmly packed scoop weighs more.