In a large mixing bowl, whisk together the 2 ½ cups whole wheat flour, ½ cup granulated sugar, ½ teaspoon fine sea salt, and 1 tablespoon baking powder.
Work in the 8 tablespoons unsalted butter just until the mixture is very crumbly. Stir in the 1 orange zest and the 1 ½ cups chopped rhubarb.
In a small bowl, whisk together the 2 large eggs and ½ cup whole milk. Add the liquid ingredients to the dry ingredients. Stir together to combine and form a dough.
Line a baking sheet with parchment and sprinkle it with flour. Pat the dough out into a circle about ½-inch thick. Brush with a little milk if you like, and sprinkle with sugar, or leave plain.
Brush each circle with cream, and sprinkle with sugar if you like. Cut the dough into 8 wedges and carefully pull the wedges away from the center to separate them just a bit.
Place the pan of scones in the freezer for 30 minutes and preheat the oven to 425°F.
Bake the scones in the upper part of your oven for 20-25 minutes, or until they're a light golden brown. When you pull one away from the others, it should look baked all the way through.
Remove the scones from the oven, and cool briefly on the pan. Serve warm.
Notes
Keep the butter very cold. Use butter straight from the fridge, or even better, the freezer. The colder the butter, the more tender and buttery the scones.
Grate the butter. I love grating butter into the dough instead of chopping it up. This is what helps to make the scones flaky; as you work the butter into the dough, some pieces will stay small, while others will soften and absorb into the dough, creating tenderness.
Make-ahead instructions. After placing the scones in the freezer, transfer them to an airtight container and freeze for up to 2 months. Bake directly from frozen.
Refined sugar-free. Use coconut sugar, honey, or maple syrup instead of granulated sugar.
Dairy-free or vegan. Substitute very cold coconut oil or your favorite non-dairy butter for the butter and use non-dairy milk. I have not tried making a vegan version of this recipe, but I think using 2 flax eggs would work well. Let me know!