In a greased round 7-inch pan, whisk together flour, sugar, salt, and baking soda.
In flour mixture, make two smaller holes and one bigger hole.
Put vanilla in in one of the small holes and the vinegar in the other.
Pour the vegetable oil in the larger hole.
Evenly pour water over top.
Whisk all ingredients together until they are smooth.
Bake for 40 minutes or until a toothpick comes out clean.
Allow cake to cool for 20 minutes before flipping it out.
Repeat process to make the second layer.
Place one of the cakes on a plate and frost the top.
Put the other cake on top of the frosting.
Frost the sides and top of the two-layer cake.
Use your hands to press the sprinkles into the sides of the cake and sprinkle some over the top.
For the Frosting
Beat butter and salt together for 2 minutes or until fluffy.
Add powdered sugar 2 cups at a time, mixing in between.
Add vanilla and beat well.
Add heavy whipping creamy and mix until frosting is uniform.
Notes
Try frosting the cake over a sheet pan lined with parchment paper, allowing you to easily capture and reuse the sprinkles that fall off the cake.I sometimes decorate the frosting in the middle of the individual cake pieces with a few more sprinkles, too!To make a cake in a 9x13 inch pan, you will need to double this recipe.