Preheat the oven to 350°F. Grease an 8-inch square baking pan and set aside.

In a medium bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon. Set aside.

In a small bowl, combine granulated sugar and lemon zest. Rub together with your fingers until fragrant. Using an stand mixer, cream together the butter and sugar mixture until fluffy, about 3 minutes. Add in the eggs, one at a time, beat until smooth. Beat in the vanilla extract and Greek yogurt. Mix until well combined.

Slowly add in the dry ingredients. Mix until just combined. Gently fold in the blueberries.

To make the streusel topping and filling, place the flour, brown sugar, and cinnamon in a medium bowl and stir well with a wooden spoon. Work the butter into the mixture with your fingertips until evenly distributed.

Pour half of the coffee cake batter into the prepared cake pan, the batter will be thick. Sprinkle half of the streusel topping/filling over the cake batter. Spoon the remaining batter over the filling, spreading gently. Sprinkle with the remaining streusel.

Bake until golden and a toothpick inserted in the center comes out clean, about 45 minutes. Cool to room temperature. Cut into squares and serve.

Note-you can replace the Greek yogurt with sour cream, if desired. Fresh or frozen blueberries work well in this recipe.