1. Preheat oven to 400 degrees. Spray a baking sheet with nonstick cooking spray. 2. In a large bowl, whisk together the flour, sugar, baking powder, lemon zest and salt. With a pastry blender or a large fork, cut in the butter until the mixture resembles coarse crumbs. 3. Blend sour cream and lemon juice into crumb mixture. 4. Divide dough in half. 5. Stir white chocolate chips into one half and blueberries into the other half. 6. Turn out dough on a floured surface. Pat or roll into an 8" circle about 1/2" thick. Place on baking sheet. With a knife or spatula cut dough into 1/8ths. 7. Whisk egg and paint on top of dough with pastry brush. Sprinkle tops with True Lemon and raw sugar. 8. Allow dough rounds to rest at least 10 minutes. 9. Bake for 12 minutes or until golden brown. Move to wire racks to cool.