Step 1

Preheat oven to 325 degrees. Grease and line a 9 x 13 inch baking pan with parchment paper; set aside.

Step 2

In a large bowl, use an electric mixer to mix together the butter and sugar until light and fluffy, about 2 minutes. Then, add in the eggs and mix until well combined. Add in the Greek yogurt and mix to combine. Mix in the baking powder, baking soda, and salt. Stir in the flour, using a rubber spatula to ensure all of the ingredients are well combined.

Step 3

For the cinnamon streusel, in a separate bowl, mix together the flour, brown sugar, cinnamon, and salt. Add in the cold cubed butter and use your hands or a fork to work the butter into the dry ingredients until the mixture resembles a coarse crumble.

Step 4

Spread half of the batter into the bottom of the baking pan. Sprinkle on half of the cinnamon streusel mixture. Dollop on the remaining batter and spread over the top using a knife. Sprinkle on the remaining cinnamon streusel mixture. Bake for 35-40 minutes, or until a toothpick inserted in the center of the coffee cake comes out clean.