Preheat the oven to 425°F (220°C). Line the muffin pan with paper liners and lightly grease with non-stick spray. Set aside.

Combine brown sugar, ground cinnamon, and a pinch of salt in a small bowl and set aside.

Combine flour, brown sugar, and cinnamon in a bowl. Add butter and mix until the mixture clumps together. Set aside.

Add flour, baking powder, and salt in a medium bowl and whisk until well combined.

In a large bowl, add melted butter, sugar, and sour cream. Whisk until well combined.

Add milk and vanilla and mix together until the mixture is smooth.

Add flour mixture to the wet and gently mix until everything is well incorporated. Do not overmix.

Drop 2 tablespoons or a large spoonful of batter into the prepared muffin tins, filling them about ½ of the way.

Drop a large spoonful of the cinnamon-sugar mixture over the bottom layer of the batter. Top the brown sugar mixture with the remaining muffin batter to fill the muffins up about ¾ of a way. Be careful here, and do not fill the batter all the way to the top.

Finally, top each muffin with a large spoonful of streusel topping, gently pressing into the top of the muffin batter so it sticks.

Bake the muffins for 5 minutes at 425°F (220°C). Then turn the oven down to 350°F (180°C) and bake for an additional 14-16 minutes, or until a skewer inserted in the center comes out clean.

Remove from the oven and allow the muffins to cool completely before serving.

Eggless Coffee Cake Muffins stay well at room temperature, tightly covered, for 3-4 days.

You can refrigerate the leftover muffins for up to a week. Allow them to come to room temperature before serving. Or, microwave the refrigerated muffins for 15-20 seconds and enjoy!