2-4tablespoonsheavy creamyou can use half-and-half or whole milk
Instructions
Cake
Preheat oven to 350. Butter and flour two 9-inch cake pans.
Stir one tablespoon of flour into the 1/2 cup of sprinkles to coat them then set aside. Sift remaining flour and salt into large bowl. Add sugar and whisk until blended.
Combine butter and water in a saucepan. Bring to a boil and pour over the flour and sugar, whisking until blended. Add the soda, buttermilk, eggs, and vanilla, and whisk until blended and smooth. Gently stir in the coated 1/2 cup of sprinkles.
Pour batter into greased and floured baking pans. Bake for 20-25 minutes, checking cake after about 15. Cake is done when tester comes out clean but be careful not to overcook.
Remove pans from oven and allow to cool on a rack for 15 minutes, then turn layers onto parchment covered racks to cool completely.
In bowl of stand mixer and using the paddle attachment, cream butter until light and fluffy about 4 minutes. Add confectioner's sugar, a little at a time (about ½ cup), mixing on low until blended and then whipping on high for about 30 seconds each time. Add vanilla and pinch of salt and mix until blended. Add cream and mix on low until blended then whip on high until frosting reaches desired consistency.
For softer frosting, you can add a little more cream. If you get it too soft just add a little more confectioner's sugar.