• Preheat oven to 350°F. Grease a 9-inch x 13-inch pan.

Crumb Topping:

• In a medium bowl, stir together 1 cup brown sugar, 1/2 cup granulated sugar, 1/2 teaspoon salt and 1 1/2 Tablespoons cinnamon. Add the melted 1 cup butter and stir until well combined. Using a fork, mix in the 2 1/2 cups flour until well combined and crumbs form.

Cake:

• Mix together the 2 1/2 cups flour, 3/4 teaspoon baking powder, 1 teaspoon baking soda and 1/2 teaspoon salt in a medium size bowl until well combined, set aside.
• Using an electric mixer, cream the 1 1/2 sticks butter until smooth. Slowly add in 1 1/2 cups sugar and beat until fluffy. Incorporate 2 eggs and scrape down the sides of the bowl. Add 1 1/4 cups greek yogurt and 1 teaspoon vanilla and beat until just combined. Slowly add in the dry ingredients and beat until fully combined.
• Pour the batter into the prepared pan and top with large chunks of the crumb mixture.
• Bake for 45-50 minutes, until a fork inserted into the middle comes out clean.