1cupsour milk (to make sour milk add 1 tablespoon lemon juice or white vinegar to 1 cup measure and top off with milk, let sit for about 10 - 15 minutes)(245 grams)
*If using unsalted butter then add ½ teaspoon of salt.
Pre-heat oven to 325° (160° celsius)
In a small bowl mix together brown sugar and cinnamon, set aside.
In a large bowl cream butter and sugar, then add the eggs, beat until fluffy.
In a medium bowl sift together flour,baking powder, baking soda and salt.
Add dry ingredients alternately with sour milk, ending with sour milk to creamed mixture. Add vanilla and mix well.
Spoon 1/3 of the batter into a greased 8" (20.5 centimeter) springform pan. Sprinkle with 1/2 of the cinnamon mixture. Spoon another 1/3 of the batter on top, then remaining cinnamon mixture and then top with the remaining batter. Bake for approximately 50-60 minutes or until toothpick comes out clean and dry. Remove from oven and let cool. Enjoy!