Heat the oven to 300°F convection (325°F conventional). Spread the pecans onto a baking sheet, and toast until fragrant and lightly brown, 8 to 10 minutes. Transfer to a cutting board. When cool, chop coarsely and transfer to a large mixing bowl.
Spread the oats onto the baking sheet, and toast, shaking and stirring halfway through, until toasty and slightly darker, 6 to 8 minutes Transfer to the bowl with the pecans. Let cool.
In a separate bowl, whisk together the butter, milk, orange zest, vanilla, and egg.
Once the oats and nuts are cool, add the flour, sugar, flaxseed, baking powder, salt, cardamom, and apricots. Stir to combine. Add the wet ingredients to the dry, stirring until thoroughly mixed.
Line 2 baking sheets with parchment paper, and scoop the scones onto the sheets, using a scant 1/4-cup measure (or 2-oz scoop), spacing about 2 inches apart. If needed, use floured hands to gently flatten the scones to 1 1/2 inches thick. Chill the scones for at least 30 minutes and up to 8 hours (this helps them leaven as they bake).
Heat the oven to 350°F convection (375°F conventional). In a small bowl, whisk together the egg and milk (or cream) for the egg wash. In a separate bowl, combine the sugar and cinnamon.
Brush the tops of the scones with egg wash, and sprinkle with cinnamon sugar. Bake until golden, 16 to 18 minutes. Serve warm, or let cool on a wire rack.