For the cake:

1. Preheat the oven to 350 degrees F. Grease and flour (or spray) two, 6 inch round cake pans that are 2 inches deep. (Make sure you are using the correct sized pans as this is important. See the notes section below.)

2. Set the butter out, cut it into chunks and allow it to come to room temperature. Do not microwave it, it needs to come to room temperature on its own.

3. In a large mixing bowl, add the dry ingredients (flour, sugar, baking powder and salt) and whisk together.

4. In another bowl, add the liquid ingredients (oil, eggs, sour cream, milk and vanilla) and whisk together until smooth.

5. Add the chunks of butter to the dry mixture slowly and mix with an electric mixer on medium speed as you add the butter. Mix until the mixture resembles a coarse, sand-like texture. (To see the texture, watch the video within this post.)

6. Add half the liquid mixture to the dry mixture and mix on medium until well combined, only about 30-45 seconds.

7. Add the second half of the liquid mixture and mix on medium until well combined, only about 20-30 seconds.

8. Scrape down the sides of the bowl and then mix again just until all the ingredients are well incorporated. Be very careful not to over-mix. Do not mix over 20 seconds here. If scratch cake batter is mixed for too long it will cause a dense cake or one that falls in the middle.

9. Add the batter to the prepared pans and smooth level. Bake at 350 degrees F for approximately 40-45 minutes (ovens vary). The batter will rise all the way to the top. Make sure you’re using the proper sized pans.

The cake layers are baked when they are golden brown and a toothpick inserted into the center of each layer comes out with a few moist crumbs on it, or clean, but not raw batter.

10. Cool on a wire rack, in the pans, for about 10-15 minutes, then turn the cakes out onto the racks and allow them to cool completely before covering with buttercream.

The tops of these cake layers will flatten out as they cool, but the tops can be leveled with a knife if needed in order to decorate.

For the buttercream :

1. In a large mixing bowl, cream the butter with an electric mixer on medium speed until smooth.

2. Scrape down the sides of the bowl and add the confectioner’s, salt, vanilla and 2 tablespoons of milk and mix on low until combined, then on medium to medium-high until well mixed.

3. Scrape down the sides of the bowl and mix again.

4. Check the consistency. If it’s too thick add another tablespoon of milk and mix well.

5. Spread buttercream onto completely cooled cake and decorate as desired.