Combine flour, sugar, baking powder, baking soda, and salt in a large mixing bowl.
2 cups unbleached all purpose flour, 1 cup sugar, 1 teaspoon baking powder, 1/2 teaspoon baking soda, 1/2 teaspoon salt
In another bowl, combine the eggs, softened butter, and vanilla. Beat until fluffy.
2 eggs, 1/2 cup butter, 1 teaspoon vanilla extract
Pour the wet ingredients into the dry ingredients and mix until combined. Don’t overmix.
Peel the apples and core them. Slice the apples into tiny pieces. Fold the apples into the batter.
1-1/2 cups chopped, peeled apples
Filled greased muffin cups or muffin liners 3/4 full and then cover with the crumbly streusel before baking.
Streusel Instructions
Combine the brown sugar, flour, cinnamon, and butter and sprinkle over the top of the muffins.
1/3 cup brown sugar, 1 tablespoon unbleached all purpose flour, 1/4 teaspoon cinnamon, 1 tablespoon butter
Bake at 375 degrees Fahrenheit for 20 minutes.
Drizzle
Combine the confectioner’s sugar, milk, melted butter, vanilla, and salt and whip until combined. After muffins are cool, drizzle the icing back and forth over the muffins and enjoy!