⅓cupmilkplus an additional tablespoon (100 ml total)
¼cuprolled oats(25 grams)
For Streusel Topping
¼cupflour(30 grams)
¼cupbrown sugar(66 grams)
¼cupsugar(49 grams)
1tspground cinnamon
pinchsalt
2Tbspunsalted buttervery cold (26 grams)
Instructions
Preheat the oven to 375°F (190°C). Line a muffin tin with liners.
Make the streusel topping first: combine the flour, both sugars, salt, and cinnamon. Cut the butter into chunks and rub together (either with your hands, a pastry cutter, or a fork) until the texture is sandy. Set aside.
Now make the muffins. In a mixing bowl, combine the flour, oats, baking powder, and sugar. Zest the entire lemon into the bowl and stir well.
Melt the butter and set aside to cool a bit. Peel the apple and slice into very small bits - think raisin-sized or smaller.
Beat the eggs & milk together and then add the mixture to the dry ingredients. Stir gently until just combined. Add butter and apples and stir again until just combined.
Spoon the mixture into the tin evenly. Top with a spoonful of streusel topping and gently press a bit into the top of the muffins.
Bake for 25-30 minutes or until a toothpick comes out clean. Allow to cool in the muffin tin for five minutes, then remove to a cooling rack.