A splash of almond extract totally transforms a basic muffin into a sophisticated, classy accompaniment for teatime.
Swap option: Yogurt can be substituted for the sour cream and walnuts or pecans can be added instead of almonds. The recipe is so versatile, try adding blueberries or chopped strawberries!
Place a rack in the upper third of the oven and preheat to 350°F. Line a 12-cup muffin tin with liners.
For the crumble:
In a medium bowl, whisk together the flour, brown sugar, cinnamon, nutmeg and salt. Add the butter and, using your fingers, quickly rub it into the dry ingredients. Some butter pieces will be in large bits; that's great. Set aside.
For the muffins:
In a medium bowl, whisk together the browned butter, sour cream, egg, egg yolk, and vanilla and almond extracts.
In a separate medium bowl, whisk together the flour, sugar, baking powder and salt. Add to the butter mixture and stir gently to combine.
Spoon half of the batter into the muffin cups. Sprinkle 1 heaping tablespoon of crumble into each cup and then top with the remaining batter. Sprinkle another tablespoon of crumble on top of each muffin, and sprinkle each with chopped almonds. Using a knife, gently swirl the crumble into each muffin.
Bake for 18 to 20 minutes, until golden brown; a toothpick inserted into the center of a muffin should come out with just a few moist crumbs. Transfer the pan to a wire rack and let cool for 15 minutes before removing the muffins from the pan. The muffins are best served warm the day they are made, but they'll keep for up to 4 days well wrapped at room temperature.