Preheat oven to 350 degrees F and line a cupcake tin with 12 liners.
Measure out 200 g of drained lychee from the can. If you don't have a kitchen scale, this will be about the entire can, minus 4-5 lychees.
Puree the lychee in a blender. You should have about 3/4 cup of lychee puree.
Cream butter, baking powder, baking soda, salt, and sugar until light and fluffy.
Add egg whites and blend until emulsified.
Mixing on low, alternate adding small batches of lychee puree and cake flour until fully incorporated.
Add almond extract and rose water and mix.
Scoop batter into cupcake liners and bake for 25-30 minutes, or until an inserted toothpick comes out clean.
Let cool while preparing the buttercream.