Streusel Ingredients

8 ½ oz all purpose flour

6 oz dark brown sugar

1 tsp cinnamon

2 ½ oz turbinado sugar

¼ tsp baking powder

1 ½ sticks unsalted butter, melted

Cake Ingredients

8 ½ oz all purpose flour

2 tsp baking powder

½ tsp baking soda

1 tsp kosher salt

6 ½ oz granulated sugar

1 stick unsalted butter, sliced

3 large eggs

2 tsp vanilla extract

1 cup sour cream

Powdered sugar

Streusel Method

In a large bowl, add 8 ½ ounces of all-purpose flours, 6 ounces dark brown sugar, 1 teaspoon of cinnamon and whisk together until homogenous and no large lumps remain.

Once completely mixed, add 2 ½ ounces of turbinado sugar, ¼ teaspoon of baking powder, and whisk together until homogenous.

Once mixed, add 1 ½ stick (12 tablespoons) of melted unsalted butter and combine with some forks or bare hands until a crumbly consistency is reached. Cover and place to the side.

Cake Method

In a bowl goes 8 ½ ounces of all-purpose flour, 2 teaspoons of baking powder, ½ teaspoon of baking soda, 1 teaspoon of kosher salt (or ½ teaspoon of table salt). Whisk together until combined.

In a stand mixer bowl, combine 6 ½ ounces of granulated sugar and 1 stick of room temperature unsalted butter (sliced into pieces). Mix together on low speed. Once combined, beat together at medium-high speed for 2-3 minutes.

Once combined, scrape down the sides of the bowl and add 3 large eggs, 2 teaspoons of vanilla extract, and 1 cup of room temperature sour cream and beat together for 1-2 minutes on medium speed, scraping down the sides of the bowl halfway through to make sure everything gets mixed in.

Once completely mixed together, sift in the dry ingredients, making sure there are no lumps, and mix on medium-low speed, scraping down the sides of the bowl after about 30 seconds, and mixing for an additional 30 seconds, until smooth.

Turn your oven on to 350°F.

Spray and wipe a pan with non-stick spray and line with parchment paper. Spray the parchment with non-stick spray so the cake doesn’t stick to the paper.

Into the 9x9 pan goes half the cake batter. Then sprinkle in about ⅓ of the streusel, pressing down gently into the batter and using a rubber spatula to shove the streusel away from the edges.

Add another layer with the remaining batter and even out before adding as much of the streusel as possible or desired.

Place in a 350°F oven with the rack set to its lowest position for 1 hr 15 minutes, until crispy and brown. Test with a cake tester to ensure that it’s done.

Let the cake cool in the pan for 45 minutes before removing using the parchment paper and allow to cool completely on a wire rack up to 90 minutes.

While it is still slightly warm, dust the cake with powdered sugar and let it finish cooling.

Once cooled completely, slice and serve.