Preheat the oven to 350°F. Spray two 8” round cake pans with non-stick baking spray; line the bottoms with parchment paper and set aside.

Combine flour, baking powder, salt, and baking soda in a bowl and set aside.

In a separate bowl, cream together butter and granulated sugar until pale and fluffy.

Add the oil and vanilla extract and beat 1 minute longer until creamy.

Beat in 1 egg at a time until mixture is fluffy and fully combined.

Rotate between adding the buttermilk and the flour mixture until cake batter is combined.

Divide the batter between the two prepared pans. Bake for 30-35 minutes, until a toothpick inserted in the cakes comes out with a few crumbs.

Cool cakes on a cooling rack for 30 minutes, then carefully remove from pan and cool completely.

To prepare the frosting, beat softened butter with a hand mixer or standing mixer until fluffy and lightened in color (about 2 minutes).

Add in the powdered sugar, one cup at a time, mixing on low speed and gradually increasing to keep the powdered sugar in the bowl.

Add in the vanilla extract and heavy cream and beat on high speed until light and fluffy (2 minutes).

Place the first layer of cake on a plate or cake stand. Spread a layer of frosting about ½” thick over the cake (about 1 cup of frosting).

Place the second layer of cake upside down on top of the first.

Mound the remaining frosting on top of the cake and spread across the top and down the sides or decorate as you wish.