2-3teaspoonsmilk (or buttermilk for tang) or water
Instructions
Muffins:
Preheat oven to 375 degrees Fahrenheit. Line a standard sized muffin pan with 12 muffin papers or grease generously. Set aside.
Make the cinnamon swirl filling. In a small bowl mix together brown sugar, cinnamon, and pinch of salt until fully combined. Set aside.
Make the streusel topping. Using your hands, two knives, or a pastry blender cut the butter into the sugar and flour until you have small pea sized chunks of butter. Add in the cinnamon, salt, and oats, mix until totally incorporated. If your kitchen is warm, place in fridge until ready to use.
Start making the cinnamon muffins. In a medium-sized bowl, whisk together the dry ingredients—flour, salt, baking soda, and cinnamon.
Drop 1- 1 ½ tablespoons of muffin batter in the bottom of each muffin paper. Take your cinnamon-sugar mixture for your cinnamon swirl and generously top the batter with the cinnamon sugar. You may have a little bit of cinnamon sugar leftover.
Top off the cinnamon swirl with more muffin batter, evenly dividing the batter between the muffin papers. Top off each muffin with streusel topping. Bake for 17-20 minutes.
While the muffins are baking, make your glaze. Whisk together powdered sugar, vanilla, and milk until smooth. Let the muffins cool for at least 10 minutes before drizzling the glaze over top of the muffins.
Video
Notes
Use cold butter. Using cold butter is essential of r a crunchy, crumbly, streusel topping. Cold butter keeps the streusel topping in its crumbly formation while it bakes. I recommend you place the streusel in the fridge or freezer while you make the muffin batter until you are ready to use it.
How to make buttermilk substitute for 1 cup of buttermilk:
1 cup milk + 1 tablespoon Lemon juice or white vinegar—let mixture stand for 10 minutes
¾ cup plain yogurt + ¼ cup water
⅔ cup plain Greek yogurt + ⅓ cup water
Pro Tip: After trying out all these different substitutes over the years, I believe that Greek yogurt + water is the best buttermilk substitute and is the closest to real buttermilk.Storage Tips. These buttermilk cinnamon streusel muffins can be stored at room temperature, but are best eaten within 3 days of making. Once they are completely cool, keep them tightly covered to prevent them from drying out. If you cover them before they are cool the muffins will end up soggy.