Preheat oven to 375°F. Line cookie sheet with parchment. Combine first 5 ingredients in processor. Add butter and cut in until mixture resembles fine meal. Transfer to large bowl. Mix in oats and currants. Add 10 tablespoons buttermilk and mix just until dough comes together, adding more buttermilk by tablespoons if dry. Turn dough out onto floured surface. Pat into 1 inch thick round. Cut out rounds using 3 inch cookie cutter. Gather scraps; pat into 1 inch thick round. Cut out more scones. Transfer scones to prepared cookie sheet, spacing 3 inches apart (scones will spread during baking). Brush generously with egg glaze. Bake scones until brown, about 30 minutes. Cool slightly on rack. Serve scones warm. BAKE 53