Preheat your oven to 350 degrees, with rack in center position. Spray and line the bottom of your cake pans with parchment paper and spray again, generously, with non-stick baking spray. Using a large bowl, whisk together the flour, baking powder, baking soda, and 1 teaspoon salt. Set aside.
Using your stand mixer fitted with the flat beater attachment, beat together the butter and sugar on medium high speed until pale and fluffy, scraping down sides of bowl as needed, for about 2 minutes. Reduce the speed to medium, and add the eggs, 1 at a time, beating well after each addition.
In a separate bowl, whisk together the sour cream, almond milk and vanilla. Going back to the stand mixer, add in the flour mixture, alternating with the sour cream mixture, beginning and ending with the flour mixture.
Evenly divide the cake batter between the pans. Bake, rotating halfway through, until tops spring back when gently touched and a cake tester inserted into centers comes out clean, for about 28 to 30 minutes; will vary depending on the size of your cakes. Transfer to wire racks, and let cool in pans for 20 minutes.
Run a knife around edge of cakes, and invert onto racks; remove parchment, and let cool completely. If wanting to level or slice cakes in half, chill the cake in the refrigerator for at least an hour. Watch the video to see how we leveled our cakes. You will need a good, large serrated knife. To slice your cakes in half, for thinner layers: use a small knife to score each layer in half horizontally. Then use a large serrated knife to slowly cut all the way through each layer, using the scored line as a guide.