Preheat oven to 350 degrees F. Spray three 8-inch or four 6-inch pans with nonstick spray, line the bottoms with parchment paper and spray again. Set aside.
In a medium bowl, whisk together the flour, baking powder and salt. Set aside.
In a small bowl, mix together the buttermilk, honey and vanilla. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium speed until fluffy, about 4 minutes.
Add eggs, one at a time, beating well after each addition and scraping down the sides of the bowl as needed.
Gradually add in the dry and wet ingredients, alternating between the two, starting and ending with the dry ingredients. Mix until just combined.
Evenly divide the batter between the three cake pans (about 16 to 17 ounces in each 8-inch pan or 12 ounces in each 6-inch).
Bake for 20 to 23 minutes, until toothpick inserted into the center comes nearly clean
Let cool in pans for 5-10 minutes, then remove to wire rack to finish cooling.