In a large mixing bowl, combine 2 and ¼ cups flour, ¼ cup sugar, 1 tablespoon baking powder and ½ teaspoon salt.
Scatter ½ cup (115g) cold butter pieces on top, and, using a pastry cutter or your hands, cut in the butter and integrate it until the mixture is crumbly and the butter is the size of peas.
Stir in ½ teaspoon orange or lemon zest.
In a medium bowl or jar, stir 1 egg, ¾ cup half-and-half and ¼ teaspoon vanilla. Mix just until combined, but don’t beat.
Fold the wet ingredients into the flour mixture and stir to combine. Don’t overdo it; the batter will be a little lumpy, and that is fine.
Scoop out 9 equal portions of biscuit batter onto the parchment-lined baking sheet. Shape into a round disc as best as possible. They will be irregular.
Bake for 15-20 minutes or until the tops are golden brown and dry. Check the inside to make sure they’re fully baked.
Cut while still warm but not hot (they crumble less), and then allow them to cool completely on a wire rack before filling.