Preheat oven to 350 and spray a 9x13 inch pan with baking spray.
Add all crumb ingredients to a mixer and mix until crumbly. Set aside.
In separate bowl combine flour, baking powder, and salt. Set aside.
Place bananas in mixer. Mix until pulverized and liquified. Add butter and sugar. Mix until combined. Next add eggs and vanilla. Mix until combined.
Add flour, milk, and cream. Mix until combined.
Pour half of batter into baking pan. Top with half of crumb. Spread remaining half of batter on top. Add 1 cup of oats to remaining crumb. Spread on top of cake.
Bake for 50-60 minutes, or until a tester comes out with moist crumbs.
Let cool for 15 minutes and then drizzle with glaze.