Makes 8 scones
1 cup hazelnuts
1 stick cold unsalted butter
3 cups all-purpose einkorn flour, plus more for dusting
1⁄4 cup granulated sugar
3⁄4 teaspoon kosher salt
1 1⁄2 teaspoon baking powder
1 Tablespoons plus 2 teaspoons coarsely chopped fresh rosemary
1⁄2 cup buttermilk
1⁄2 cup heavy cream, plus more for brushing
3 Tablespoons honeycomb
Turbinado sugar, for topping
Preheat the oven to 350°. Toast hazelnuts on a baking sheet until the skins are dark, 10 to 12 minutes (you can usually smell when they’re ready). Take out of oven and set aside until they’re cool enough to handle. Rubbing between hands remove and throw away as much skin a possible, then coarsely chop the nuts.
Meanwhile, grate the cold butter on the large side of a box grater; chill.
In a large bowl, whisk together the flour, granulated sugar, salt, and baking powder. Add the butter, mixing briefly with fingers to distribute. Add the chopped hazelnuts and rosemary, tossing to coat.
In a medium bowl, combine the buttermilk and heavy cream, then slowly add the mixture to the dry ingredients, stirring with a spatula to incorporate. Break up the honeycomb into small pieces with your fingers and mix into the dough by hand to distribute throughout.
On a parchment-lined baking sheet that's been lightly dusted with more einkorn flour, turn out the dough. Using floured hands, shape into a 12-inch-long, 1-inch-thick rectangle. Chill until firm, about 1 hour.
Preheat the oven to 400°. Using a sharp knife, make a diagonal cut crosswise through the dough every 3 inches to form 8 triangular scones. Separate the scones across the baking sheet, leaving at least 2 inches between each. Brush the scones with heavy cream and sprinkle each with about 1⁄4 tsp. coarse sugar.
Bake until lightly browned on the top and golden-brown on the bottom, 18 to 24 minutes.
Remove and let cool 5 minutes, then transfer to a rack to cool completely.