Collect the juice of a Florida Grapefruit using a juicer.
Heat the Florida Grapefruit Juice with the butter and honey. Let cool.
Mix the flour, baking powder, sugar and cinnamon in a bowl.
Add the mixture to the honey little by little, mixing with a whisk.
Pour into a cake tin.
Collect the segments of the half Florida Grapefruit.
Spread the granulated sugar on top of the cake and add the Florida Grapefruit segments.
Preheat your oven to 320°F and bake for 40 minutes. Test for doneness by pressing the blade of a knife. It must come out dry. If not, cook for a longer time.
