In a small bowl, make your streusal by tossing flour, white and brown sugar, cinnamon, and salt. Next, add in your cubed butter. Use your fingers to work and incorporate the butter and the flour mixture until you have your crumbly topping. Transfer to the fridge while you prep your batter.

Preheat oven to 350°F. Line a 9x5-inch loaf pan with a strip of parchment paper hanging over the sides of the pan, and take your stick of butter to spread around the pan, just a teaspoon or so of the stick of butter.

In a small saucepan over medium heat, melt the 8 tablespoons of unsalted butter.

Continue cooking, stirring consistently, until the butter foams, the foam subsides, it smells nutty, and golden-brown flecks appear at the bottom of the pan, about 5 to 6 minutes.

Transfer immediately to a large mixing bowl and allow it to cool for about 10 minutes.

To the brown butter, whisk in both sugars. Then add your mashed bananas, Greek yogurt, eggs, and vanilla extract. Whisk until completely combined.

Next, add in baking powder, baking soda, and salt. Mix well.

Lastly, add in your flour and fold gently with a spatula until just combined, being careful not to overmix. Transfer to the loaf pan and sprinkle your streusal evenly over the top of the batter.

Transfer to the preheated oven and bake for 50 to 60 minutes, until a toothpick inserted in the center comes out clean.

Remove from the oven and cool in the loaf pan for 10 minutes, then carefully transfer the banana bread to a wire rack to cool completely, about 45 to 50 minutes. Slice and serve!