Quick Single-Serve Coffee Cake

In ramekin or mug
1 tablespoon of butter softened it in the microwave (Don't melt, just soften.)
2 tablespoons of sugar stirred in until fluffy/creamy.
1/2 a beaten egg (without egg it's more crumbly and less cake-y. Can add a whole egg, or split it between two coffee cakes.)
2 tablespoons of sour cream
2-ish drops vanilla.
1/4 cup flour
1/8 teaspoon baking powder.

For crumb topping mix together in a separate bowl:
1 tablespoon butter
2 tablespoons flour
1 tablespoon of brown sugar
1 teaspoon of cinnamon
Smoosh together

Mix all ingredients. Top with crumb topping mixture, then microwave. Start with 1 minute, then do 10 seconds more until it's done to your liking. Approximately 1:20