Bake for about 10-12 minutes until the cakes begin to brown. Remove from the oven and let the cakes cool on the baking sheet for 3-5 min before transferring them to a rack to cool completely. Let them cool for a couple minutes on the baking sheet before moving them.
Put the batter into a pastry bag fitted with a large round tip, you can also use a ziploc back and just cut off one tip, and drop about 1 tablespoon of batter onto the baking sheet. Repeat making sure to leave about 2 inches in between the cakes.
In a small bowl, combine the milk, baking soda and vinegar. Add this mixture to the batter along with the flour mixture and beat on low speed until completely combined.
In a medium bowl add the flour, baking powder, cinnamon, and salt. In a mixer fitted with the paddle attachment, beat the butter, and brown sugar until light and creamy, about 3 minutes. Add the eggs, buttermilk, and vanilla and beat until well incorporated.
Preheat the oven to 375 degrees and line two baking sheets with parchment paper.