Use a regular size muffin tin. Spray with no stick spray.
Heat oven to 325.
Combine butter and sugar and blend in the blender. Add the eggs, vanilla and sour cream and continue blending. (I have a hand blender so this took a long time. I blended the ingredients on high for a good five minutes.) If you have a good stand mixer this will take less time.
In a separate bowl add flour, baking powder, salt and baking soda and stir the flour mixture then fold it into the wet ingredients until it's well blended.
Spoon into each slot of the muffin tin but only until half full.
Mix melted butter, another half cup of sugar and cinnamon together to form a drizzle.
Add that to each mini cake in progress. Hold some back to end.
Scoop the rest of the coffee cake into each muffin slot.
Add to the top of each cake the remaining sugary drizzle.
Bake for 35 to 40 minutes maximum. I kept close eye on mine because every oven is different.If you opt for a different sized container you will need to adjust baking time.
Enjoy! This makes 12 mini cakes. These would be fantastic in a tiny loaf pan too.