Blueberry Lemon Crumb Cake

1. Preheat oven to 350u0b0F. Butter and flour the inside of a 9-inch round cake pan.
2. First prepare the streusel topping. Sift the flour into a large mixing bowl. Using a pastry cutter or the tips of your clean fingers, rub the butter into the flour until the mixture resembles coarse crumbs.
3. Add the sugars and lemon zest to the mixture and mix well together. Set aside.
4. For the cake, sift the flour, baking powder, baking soda and salt together in a bowl. Set aside.
5. Using the paddle attachment of an electric mixer, cream the butter and sugar together until the butter turns a pale ivory color (about 4 to 5 minutes).
6. Add the eggs, one at a time, mixing into the butter mixture on low speed.
7. Add the vanilla, lemon zest and plain yogurt.
8. Continuing on low speed, add the flour mixture gradually, mixing slowly until combined. Do not overbeat.
9. Use a spatula to clean the batter from the sides of the bowl and gently fold in the blueberries.
10. Spoon the cake batter into the prepared cake pan. Use a spatula to level the top.
11. Sprinkle the streusel topping evenly over the cake batter.
12. Bake at 350u0b0F for 50 to 60 minutes until an inserted toothpick comes out clean.
13. Place the cake pan on a wire tray and cool for 10 minutes. Remove the cake from the pan and cool completely on a the wire tray.
14. Serve plain for breakfast or with a dollop of fresh whipped cream.