Preheat the oven to 325°F with a rack in the center. Lightly butter two 8” x 2” round cake pans. Line the bottom of the pans with parchment circles the same size as your cake pans and butter the parchment. If your 8” pans aren’t at least 2” deep, use 9” pans.
In a small bowl sift together the flour, salt, and baking powder then whisk to combine. Set aside.
In the bowl of a stand mixer a stand mixer fitted with the whisk attachment, beat the eggs, sugar, vanilla, lemon extract, and lemon zest until thickened and light gold in color, about 2-3 minutes at medium-high speed. The batter should fall in thick ribbons from the whisk.
Add the dry ingredients to the bowl with the egg mixture and mix on low speed until just combined. Scrape down the bottom and sides of the bowl and mix once more just to make sure everything is incorporated.
Heat milk in a saucepan over medium-high heat until it just comes to a simmer. Remove the pan from the heat and add the butter and oil, whisking until the butter has melted.
Slowly mix the hot milk mixture into the batter, mixing on low speed until everything is well combined. Scrape down the bowl and mix again just until smooth.
Divide the batter evenly between the two pans. Bake the cakes until the edges are pulling away from the sides of the pan and a toothpick inserted into the center comes out clean, 26 to 30 minutes for two 9” pans, or 38 to 42 minutes for two 8” pans. Remove the cakes from the oven, carefully run a butter knife around the edges of the pan to loosen the edges, and allow cakes to cool for 15 minutes in the pans. Then transfer cakes to a wire rack to cool completely.