Preheat oven to 325°F. Grease and flour two 8-inch round cake pans.
Whisk together oil, vanilla, buttermilk, lemon zest, lemon extract, and 1–2 drops yellow coloring.
Whisk flour, salt, baking powder, and baking soda in separate bowl.
In large bowl, mix butter and sugar until light and fluffy.
Add eggs one at a time, fully incorporating each before adding next.
Gradually add flour mixture to butter mixture in three additions, alternating with buttermilk mixture.
Gently fold in 1–2 drops yellow gel food coloring.
Divide between prepared pans and smooth surfaces.
Bake 25–30 minutes until toothpick inserted comes out clean.
Let cool in pans 10 minutes, then invert onto cooling racks to cool completely.
For frosting, beat cream cheese until smooth.
Add unsalted butter and beat until fluffy.
Add lemon extract, lemon zest, and a pinch of salt.
Mix in powdered sugar and lemon juice to desired consistency.
Use yellow gel food coloring as needed.
Once layers are cooled, spread frosting between layers and around sides.