Strawberry Shortcake with Grand Marnier Strawberry Compote and Chantilly Cream

In large bowl, sift together all-purpose and cake flours, sugar, baking powder, and salt. Use pastry cutter or fork to blend in butter until mixture resembles coarse meal. In medium bowl, whisk together buttermilk and cream, then whisk in lemon zest. Add liquid mixture to dry mixture, stirring with fork just until dough forms. Turn dough out onto floured work surface and knead gently just until dough holds together, about 10 turns. Place dough on plate, cover with plastic wrap, and refrigerate until well chilled, at least 30 minutes. Preheat oven to 400 °F. On floured work surface, pat out dough to 1/2-inch-thick round. Using 3-inch cutter, cut out biscuits. Transfer to ungreased baking sheet, brush lightly with cream, and sprinkle with sugar. Bake until golden brown, 15 to 18 minutes, then transfer to rack to cool.