01 -
Heat your oven to 375°F and line up a 12-tin muffin pan with liners.
02 -
In a small dish, whisk together sugar, cinnamon, and flour. Toss in the butter and mix with a fork till you've got a crumbly texture. Chill in the fridge for later.
03 -
Use a large bowl and mix together flour, sugar, lemon zest, salt, and baking powder.
04 -
In another big bowl, stir together the butter, buttermilk, and egg until they're combined. It's cool if it looks a bit uneven.
05 -
Pour the wet mixture into the bowl of dry stuff and stir gently until just combined. It's supposed to look a bit lumpy.
06 -
Carefully mix the blueberries into the batter but don't overdo it or you'll smash them!
07 -
Grab a cookie scoop (3 tablespoons will do) and evenly portion the batter into the cups.
08 -
Sprinkle the crumbled streusel topping by hand on every muffin.
09 -
Place the pan in the oven for 28-30 minutes. The tops should turn golden and spring back when pressed lightly.
10 -
They're good warm, but when they cool for a couple of hours, the flavor's even better.