Pat blueberries dry with paper towels; set aside.
Combine flour and next 4 ingredients in a large bowl; cut in shortening with a pastry blender until crumbly.
Whisk together egg and buttermilk; add to flour mixture, stirring just until dry ingredients are moistened. Gently fold in blueberries.
Turn dough out onto a lightly floured surface; knead 3 or 4 times.
Pat or roll dough to 3/4-inch thickness; cut with a 2 3/4-inch round cutter, and place on a lightly greased baking sheet.
Bake at 400° for 15 minutes or until biscuits are golden brown. Stir together butter, 2 tablespoons sugar and cinnamon; brush mixture over warm biscuits.
NOTE: Recipe can be doubled. Store biscuits in an airtight container for up to 3 weeks in freezer.