Buttery banana cake filled with sweetened cinnamon swrils, topped with a crunchy cinnamon streusel and an easy vanilla glaze. It's best enjoyed warm with cup of coffee.
Make the streusel by combining dry ingredients together. Work the butter into the dry mixture until its the consistency of wet sand. To make the filling, whisk together the brown sugar, cinnamon and cocoa powder until very well combined.
In a stand mixer with whisk attachment (or by hand), beat butter and sugar until smooth and well combined. Add eggs, beating well after each one until well combined. Add mashed bananas and vanilla extract, beating until well combined.
In this order (dry ingredients, yogurt, dry, yogurt, dry), add dry ingredients to the wet alternating with the yogurt. Slowly beat each time until JUST combined.
Pour 1/2 of the banana cake batter into the prepared pan. Scatter most of the cinnamon filling over the batter. Create siwrls and repeat. Top with the streusel.
Bake at 350F for 45 minutes. Check the topping. Return to the oven for 10-15 minutes, checking for doneness every 5 minutes (55-65 minutes total). Cool in pan for 20 minutes. Gently remove from the spring form pan. Cool an addtional 30-45 minutes.
Combine all glaze ingredients in a bowl until smooth and well combined. Pour over the cooled coffee cake. Allow 30 minutes for the glaze to set. Slice and enjoy with a cup of coffee!