Preheat oven to 350ºF. Lightly grease and line with parchment circles, three (8- inch) baking pans.
In a mixing bowl add the flour, baking powder and salt. Whisk to combine and set aside.
2-1/4 cups all-purpose flour, 2-1/2 tsps. baking powder, 1/2 tsp table salt
In the bowl of a stand mixer with the paddle attachment fitted (or use an electric handheld mixer) add the sugar and butter. Beat until light and fluffy - about 2 minutes.
1-3/4 cups granulated sugar, 1/2 cup unsalted butter, softened
Add the eggs, one at a time, and beat well after each incorporation. Add the vanilla extract and coconut milk and beat again until fully combined.
3 large eggs, room temperature, 2 tsps. vanilla extract, 1 cup canned, unsweetened coconut milk
Gradually add the flour mixture to the mixing bowl and beat on a slow speed until just combined.
Lastly, add the chopped pineapple and use a rubber spatula to fold it in by hand.
1 cup pineapple
Divide the cake batter between the three prepared cake pans and bake in the preheated oven for 22 minutes. (The cakes are baked when they are a pale golden brown, slightly shrinking away from the edges of the pan and a toothpick inserted into the middle comes out clean.) Remove from the oven and leave in the pans for 10 minutes then turn out onto a wire rack to completely cool.