Step 1

Preheat the oven to 400 degrees.

Step 2

Line your jumbo muffin pan(s) with liners, set aside.

Step 3

In the bowl of a stand mixer, combine the sugar and bananas.

Step 4

Mix until bananas are mashed and combined.

Step 5

Add in the egg yolks, oil and sour cream.

Step 6

Mix until combined.

Step 7

Add in the baking powder, baking soda, salt and flour.

Step 8

Mix on low speed until combined. Scrape the sides often and mix again.

Step 9

Fold in the chopped nuts.

Step 10

Measure out the muffin batter to fill the liners until they are about ⅔ full.

Step 11

For the streusel topping - In a small bowl, combine the brown sugar, flour and cinnamon.

Step 12

Add in the melted butter and mix until combined.

Step 13

Add in the chopped nuts and combine.

Step 14

Sprinkle the streusel topping over the muffin batter.

Step 15

Bake in the preheated oven for 8 minutes.

Step 16

Lower the heat to 350 degrees and bake for an additional 15 minutes or until the edges are slightly browned and the center is set.

Step 17

Allow to cool slightly before removing from the pan.