• Preheat the oven to 350 degrees F.
• Grease a 9×13-inch baking pan or line with parchment paper. Set aside until needed.

Crumb Topping

• Add the flour, brown sugar, granulated sugar, cinnamon, and salt to a large bowl and whisk to combine.
• Add the melted butter to the sugar mixture, stirring gently to combine. You should have large crumbs, do not over-mix. Set aside until needed.

Cake

• Add the all-purpose flour, baking soda, baking powder, and salt to a large bowl. Whisk to combine and set aside.
• Add the butter and granulated sugar to the bowl of a stand mixer fitted with a paddle attachment, beat on high speed until smooth and creamy, about 2 minutes. Scrape down the sides and up the bottom of the bowl as needed.
• Add the eggs, sour cream, and vanilla extract to the creamed butter.
• Beat on medium-high speed until combined. The mixture may look curdled; that’s ok. Scrape down the sides and up the bottom of the bowl as needed.
• With the mixer on low speed, mix in the dry ingredients until smooth. Do not over-mix. The batter will be thick, creamy, and sticky.
• Spread the batter evenly into the prepared baking pan. Top with the crumb topping. Using a spatula or the back of a large spoon, lightly press the crumb topping into the cake so it sticks to the batter.
• Place the pan on the center rack of the preheated oven and bake for 45-55 minutes.

  *The cake is done when a toothpick inserted in the center comes out clean. If you find the top or edges of the cake are browning too quickly, loosely cover the pan with aluminum foil.
• Remove the cake from the oven and set on a wire rack.
• Cool for 30-45 minutes before cutting. Dust with confectioners’ sugar and enjoy.