These Coffee Cake Muffins are perfectly cinnamon-y, fluffy, tender, moist, are stuffed with a brown sugar, cinnamon filling, & topped with a crunchy streusel!
*Don't have buttermilk? Mix together 1 cup milk + 1/4 cup white vinegar. Let sit for 5-10 minutes, then proceed with recipe. That being said, I'd highly recommend true buttermilk, as it makes these muffins extra tender and moist!