Position a rack in the center of the oven and preheat to 325 (F). Generously spray three 8-inch cake pans with cooking spray and line the bottom of each pan with a parchment paper circle; spray the parchment paper too.
In a medium bowl, whisk together flour, baking powder, and salt.
In the bowl of a stand mixer fitted with the whisk attachment, combine eggs, sugar, and extracts. Whisk on medium-high for 3 minutes, until light, fluffy, and doubled in volume.
While the eggs and sugar are whisking, heat milk in a microwave or in a heavy-bottomed sauce pot until just about to boil. Immediately add the butter and oil, whisking until the butter is completely melted. Place a plate over the mixture as a makeshift lid to keep things warm as you work with the other ingredients.
Return to the egg and sugar mixture and reduce the mixer to low. Gradually add the dry ingredients from the first step, whisking on low until just combined, using a rubber spatula to scrape down the bottom and sides of the bowl as necessary. Slowly pour in the warm milk mixture and whisk until just combined. Divide the batter between the three cake pans (if you want even layers, use a digital scale to weigh the amount of batter as you pour into the pans—each pan will contain around 21.35 ounces of batter). Bake for 35 to 40 minutes, or until a skewer inserted into the center of each cake comes out with few crumbs attached and the cake bounces back when gently poked. Cool the cakes in their pans on a wire rack completely before frosting.