Make the dough: Preheat oven to 400° F.
Place the flours, baking powder and salt in the bowl of a food processor fitted with a metal blade and pulse until combined. Add the butter and pulse until the mixture resembles coarse meal. Add the buttermilk and zest and pulse until the dough is just combined.
Shape the scones: Line a baking sheet with parchment paper and set aside.
Place an 18-inch sheet of parchment paper on a work surface and sprinkle it lightly with flour. Transfer the dough to the paper and, with floured hands, gently press the dough into a 12-inch square; the dough should be about 3/4 inch thick. Cut out two six-inch circles, reshape the remaining dough into a 3/4-inch-thick square, and cut out one more 6-inch circle. Gather the remaining scraps and form into one final 6-inch circle. Place 1/4 cup of jam on two of the circles. Top each with the remaining dough rounds and pinch the sides shu Tbsp Using a knife, score the top of each scone with a large cross marking 4 quadrants.
Sprinkle the tops with sugar. Transfer scones to the prepared pan and bake until golden, 35 to 40 minutes. Transfer to a wire rack to cool. Split or cut on the score lines.
Serve warm or at room temperature.Servings: 16 scones