Brown the butter: Melt butter over medium heat until it turns golden brown and smells nutty (2–5 min). Pour into a bowl and chill until solid but scoopable (~15–25 min).
Mix dry ingredients: In a bowl, combine flour, brown sugar, baking powder, and salt.
Cut in butter: Cut the browned butter into small chunks and work into flour until you get pea-sized pieces.
Add wet ingredients: Whisk cream, egg, and vanilla. Add to dough and mix until just combined. Fold in white chocolate or nuts if using.
Shape + chill: Pat into a ~1 inch thick disk, cut into 8 wedges, and chill for 15–20 minutes.
Prep the tops: Brush tops lightly with heavy cream and sprinkle with turbinado sugar.
Bake: Bake at 400°F for 15–18 minutes until tops are golden and edges are set.
Glaze: Let scones cool slightly (5–10 min), mix glaze until smooth, and lightly drizzle over the top.
