Pre-heat oven to 400 degrees. Place muffin liners or squares of parchment paper into every other space in a 12 space muffin tin

In a small bowl combine the streusel ingredients; butter, salt, sugar, lemon juice, lemon paste, flour, baking powder and cinnamon. Using a fork or pastry cutter, cut the mixture together until it resembles wet sand.

Chill.

In a small bowl mix the lemon zest and sugar well with your fingers until well combined and the sugar feels sticky and somewhat wet. Set aside.

In a large bowl, combine the flour, salt and baking powder. Mix well with a whisk.

In a bowl combine the eggs, yogurt, oil and vanilla- mix well. Stir in the lemon zest and sugar mixture into the egg mixture. Using a spatula, gently fold this wet mixture into the flour mixture taking care not to over-mix. Toss the blueberries in the heaping tablespoon of flour. Fold in the flour coated blueberries into the batter.

Using a scoop, scoop out the batter into every other muffin space in your prepared baking tin. The batter should be generously mounded into the tin. Sprinkle with a tablespoon of the streusel topping. REDUCE the oven temperature to 375 degrees and bake until golden brown or about 17 minutes.

Remove from the pan and cool on a wire rack. Best served warm out of the oven.