Preheat the oven to 375F. Prepare a 12 cup muffin tin with non-stick spray or liners.
Mix the flour, baking powder, baking soda and salt and set aside.
Beat the butter, sugar and lemon zest in a mixer with a paddle attachment for 3 minutes at medium high speed. The mixture should be pale and fluffy. Gradually add in 1 egg at a time. Reduce the speed to low and alternately add the dry flour mix and the yogurt in three additions. Scrape down the bowl.
By hand, stir in the blueberries.
Make the Streusel Topping - Combine all ingredients with a fork until pea sized chunks form.
Use an ice cream scoop to divide the batter into the prepared muffin tin and top with a tablespoon of streusel topping. Bake for 15 - 20 minutes or until muffins until golden brown. Rotate the pan half way though baking.
Let muffins cool in pan for 5 minutes, then remove and cool on a wire rack for at least 5 minutes before serving.
by Karyn Granrud
Baked Muffins can be frozen and stored for up to 6 months.