How to Make It
Sift together first 5 ingredients in a large bowl. Chill 1 hour.
Line a baking sheet with parchment paper. Lightly coat parchment paper with cooking spray. Set aside.
Cut shortening and butter into cold flour mixture with a fork or pastry blender until crumbly. Add 2 cups cold buttermilk, stirring just until dry ingredients are moistened. (Dough will be light and crumbly.)
Turn dough out onto a floured surface. Pat dough into a 1-inch-thick circle, and cut with a floured 3-inch round cutter. Place shortcakes 2 inches apart on prepared baking sheet. Repeat procedure once with remaining scraps of dough.
Stir together egg yolk and 1/4 cup buttermilk. Brush mixture onto shortcake tops, and sprinkle evenly with coarse sugar.
Bake at 425° for 12 to 15 minutes or until lightly browned. Remove baking sheet to wire racks to cool.
Stir together peaches, blueberries, 1/2 cup granulated sugar, and ground nutmeg; cover and chill.
Beat 1 cup whipping cream and 3 tablespoons confectioners sugar at medium speed with an electric mixer until soft peaks form. Stir in 3 tablespoons almond liqueur, if desired.
Split shortcakes in half. Spoon fruit mixture on bottom halves of shortcakes; top with remaining halves and a dollop of whipped cream. Garnish, if desired.