Preheat oven to 375°F degrees. Line a 12 cup muffin pan with paper liners and set aside.

Combine the granulated sugar and lemon zest. Use your hands to massage the lemon zest into the sugar for 15 to 20 seconds.

In large bowl, whisk together cooled melted butter, sugar with lemon zest, eggs, Greek yogurt and vanilla. Whisk to combine well.

In a separate bowl, whisk together the flours, baking powder and salt.

Use a large spatula or wooden spoon to gently mix the dry ingredients in to the egg and sugar mixture, leaving a few streaks of flour remaining. Do not over mix.

In a small bowl toss the raspberries with 2 tablespoons of flour to coat.

Add the raspberries to the batter and gently fold to incorporate in just two to three motions. Do not over mix.

Cover the bowl with a dish towel and let rest at room temperature for 30 minutes. Meanwhile, make the streusel topping.

Divide the batter equally amongst the muffin liners, filling to the top. For best results, only fill every other muffin liner. This allows more air flow around the muffins while baking resulting in a higher rise.

Top each muffin with the cold streusel, covering generously.

Bake for 18 to 19 minutes or until the tops are slightly golden brown and a toothpick inserted into the center of a muffin comes out clean or with a few crumbs remaining. Do not over bake or the muffins will be dry.

Remove the muffins from the oven and allow to cool completely on a wire rack before adding the glaze.