Preheat the oven to 325 degrees F. Prepare three 8-inch or four 6-inch round cake pans with nonstick spray, parchment paper, and one more spray of nonstick spray.
In a bowl of electric mixer, combine all the dry ingredients. Set aside.
In a medium mixing bowl, combine eggs, buttermilk, water, oil, vanilla and peppermint and lightly beat with a fork.
With the mixer on low speed, add wet ingredients to the dry ingredients. Mix for about 30 seconds. Batter will be thin. Scrape sides and mix for another 10 to 20 seconds. Divide batter evenly among prepared pans (about 15 ounces of batter in each 8-inch pan or 11 ounces in each 6-inch pan).
Bake for 25 to 30 minutes (you may need more time depending on your oven), until toothpick comes out with a few moist crumbs on it. Cool on wire racks for 10-15 minutes and then gently invert onto greased racks until cooled completely.
When cakes are completely cooled, I like to wrap each cake layer individually with plastic wrap and stick it in the freezer until I’m ready to frost. The cake will be easier to work with if it’s cooled a bit.