• Preheat oven to 350°F. Butter an 8- or 9- inch cake pan. Line the bottom with parchment.

Pan schmear

• In the bowl of a stand mixer fitted with the paddle attachment, combine the butter, honey, brown sugar, and vanilla extract. Beat on low until mixed, then increase speed and beat until fluffy, about 3 minutes. Spread pan schmear in an even layer across the bottom of the cake pan. Lightly sprinkle with kosher salt.

Cake

• Using a chef's knife, slice the top off the pineapple, then slice off the sides. Slice off the bottom. Stand the pineapple on end and cut into quarters. Cut out the core. Slice the pineapple quarters into into slices 1/8 inch thick, and, working from the outside of the pan towards the center, layer overlapping pieces of pineapple over the pan schmear. Reserve remaining pineapple for another use.
• In a medium bowl, sift together flour and baking powder. Set aside.
• In the bowl of the stand mixer (no need to clean) fitted with the paddle attachment, beat together butter and sugar on low until mixed. Increase speed to medium and beat until light and fluffy, 3 minutes.
• Add extract and beat in. Add eggs, one at a time, beating in completely before adding the next. Beat in buttermilk or milk.
• Add the flour mixture in three additions, mixing on low just long enough to incorporate.
• Scrape batter over the top of the pineapple, using a spatula to even the surface.
• Bake 15 minutes, rotate the pan for even browning, then bake an additional 20-25 minutes, or until a skewer inserted into the center comes out clean.
• Let cake cool in pan for 20 minutes. Run a sharp knife around the edge, place a serving plate over the top and invert to release cake, then peel away the parchment.