Preheat the oven to 350°F (177°C).
Prepare the topping. Melt 1 tablespoon of coconut oil and pour it into a cast iron skillet or a round baking dish (approximately 9-inch diameter). Sprinkle brown sugar evenly over the oil.
Blot any excess liquid off the pineapple slices with a clean towel or paper towel. Then, arrange 7 pineapple slices and all the cherries on top of the brown sugar. You can also halve 3 pineapple rings and arrange them around the sides of the pan (see the photo above). Place the pan in the refrigerator for a few minutes as you prepare the cake batter. This helps to set the topping’s arrangement.
Make the cake batter. In a medium bowl, mix together the flour, sugar and baking powder. Pour in melted coconut oil, almond milk and vanilla and beat with a handheld mixer or a whisk for about 1 minute.
Remove the topping from the refrigerator. Pour and spread cake batter evenly over the topping.
Bake for 30 to 35 minutes, until a toothpick inserted in the middle comes out clean. After removing the cake from the oven, cool it in the pan on a wire rack for about 20 minutes. Then ease a spatula around the edge of the tin, place a plate on top, and turn it upside-down.
You can serve the cake warm, but I like it best when it's perfectly cool and the caramelised topping is sticky. It's also easier to cut when it's cool. You can store any leftover slices for up to 3 days in the refrigerator or 3 months in the freezer.