Easy Homemade Cinnamon Streusel Muffins Recipe

Streusel Topping
1 In a small bowl, whisk together the streusel dry ingredients of flour, both sugars, cinnamon, & salt. Then pour in melted butter and stir with a fork until it resembles wet sand.
2 Set aside - the different components will firm slightly while you mix the batter.
Muffins
4 Set the oven temperature to 400°F and line a standard muffin pan with muffin liners, or lightly grease the muffin cups.
5 In a large bowl (or large mixing bowl), whisk the dry ingredients for the batter: flour, baking powder, baking soda, cinnamon, sugar, and salt. 
6 In a separate bowl (medium bowl), whisk the wet ingredients: room temperature Greek yogurt, whole milk, large eggs, oil, and vanilla extract until smooth.
7 Make a well in the center of the flour mixture and pour in the wet ingredients. Gently fold with a spatula just until you no longer see streaks—overmixing creates dense muffins. The batter should be thick but scoopable; if it seems overly thin, you may have added too much milk or too little flour.
Assembly & Baking
8 Divide the batter among the muffin cups, filling about three-quarters full so the center of a muffin rises nicely. Generously sprinkle the cinnamon streusel topping over each portion, lightly pressing so it adheres to the top of the muffins.
10 Bake about 20-25 minutes until the tops are golden brown and a tester inserted in the middle of the muffin shows moist crumbs without wet batter.
11 Cool in the pan briefly, then transfer to a wire rack to finish cooling.