Go Back
Banana coffee cake with cinnamon streusel square on a white plate

Banana Coffee Cake with Cinnamon Streusel

Authorlily mellow
A soft, golden banana coffee cake with a thick buttery cinnamon streusel and a hidden cinnamon swirl. Made with ripe bananas and sour cream for a naturally sweet, tender crumb — perfect alongside your morning coffee.
Print Recipe Pin Recipe
Prep Time20 minutes
Cook Time42 minutes
Total Time1 hour 2 minutes
Servings9 squares
Calories320 kcal

Equipment

  • 9x9-inch square metal baking pan
  • Parchment paper
  • Large glass mixing bowl
  • Medium mixing bowl
  • Hand mixer or stand mixer
  • Silicone spatula
  • Wire cooling rack

Ingredients  

CINNAMON STREUSEL TOPPING

  • 1 cup 125g all-purpose flour
  • 2/3 cup 135g packed brown sugar
  • 1 1/2 tsp ground cinnamon
  • 1/4 tsp fine sea salt
  • 6 tbsp 85g unsalted butter, melted
  • 1/3 cup crushed Biscoff cookies optional

CINNAMON SWIRL

  • 1/3 cup 65g light brown sugar
  • 1 tsp ground cinnamon

BANANA CAKE BATTER

  • 2 cups 250g all-purpose flour
  • 1 tsp baking soda
  • 1/2 tsp baking powder
  • 1/2 tsp salt
  • 1/2 cup 115g unsalted butter, softened
  • 1/2 cup 100g granulated sugar
  • 1/3 cup 70g packed brown sugar
  • 2 large eggs room temperature
  • 1 tsp pure vanilla extract
  • 1 1/2 cups mashed ripe bananas about 3–4 medium
  • 1/3 cup 80g sour cream or full-fat Greek yogurt

Instructions 

  1. Preheat oven to 350°F (175°C). Butter a 9x9-inch pan and line with parchment paper, leaving an overhang.
  2. Make the streusel: whisk flour, brown sugar, cinnamon, and salt; stir in melted butter until crumbly. Chill.
  3. Mix the cinnamon swirl: stir brown sugar and cinnamon together. Set aside.
  4. Whisk flour, baking soda, baking powder, and salt in a medium bowl.
  5. Cream butter, granulated sugar, and brown sugar for 2-3 minutes until light and fluffy.
  6. Beat in eggs one at a time, then vanilla. Mix in mashed bananas and sour cream.
  7. Fold in dry ingredients until just combined.
  8. Spread half the batter in the pan, sprinkle with cinnamon swirl, cover with remaining batter, then top with chilled streusel.
  9. Bake for 40-45 minutes, until a toothpick inserted into the center comes out clean.
  10. Cool in the pan for 20 minutes, then lift out and cool completely before slicing.

Notes

Note 1 : Storage — keeps up to 5 days refrigerated in an airtight container, or 2 months frozen (wrap squares individually).
Note 2 : Substitution — sour cream can be swapped for full-fat Greek yogurt or thick buttermilk.
Note 3 : Chill the streusel while mixing the batter for the crunchiest topping.