preheat oven 350f. oil a 9 in round cake pan with tall sides, an dust it with 3 tablespoons bread crumbs. using a grater, zest both grapefruits. juice 1 of the grapefruits to 1/4 cup juice. in a small bowl, mix the zest, juice, and olive oil. set aside
in a lrg bowl, beat the eggs and salt till they are light and fluffy. slowly beat in the sugar and honey, and continue to mix until pale and thick. about 2 min more. in a seperate bowl, sift the flour an remaining 1/4 cup breadcrumbs, and the baking powder. then slowly beat the dry ingrediances into the egg mixture. fold in the citrus zest mixture just till combined.
pour the batter into the baking pan. bake for 50 min or until a toothpick comes ut clean. let the cake cool in the pan to room temp an serve ummmmmmm