|Preheat oven to 450 degrees F.
Into pie plate or shallow baking dish, grate orange to make 1 tablespoon grated peel. Into measuring cup, squeeze juice from orange; add 1/3 cup juice to orange peel with eggs and cardamom; with fork or wire whisk, beat until mixed.
Melt 1/4 cup butter or margarine in the oven in a 15 1/2 x 10 1/2-inch jellyroll pan; remove from oven.
Dip half of bread slices into egg mixture to coat all sides; place in one layer in buttered jellyroll pan. Bake 5 minutes on each side until lightly browned.
Arrange on heated platter; keep warm.
Melt 1/4 cup butter or margarine in same jellyroll pan; repeat dipping and baking remaining bread.
In small saucepan over medium-low heat, melt orange marmalade with 2 tablespoons reserved orange juice, stirring occasionally. Pass warm marmalade mixture and confectioners sugar.
Makes 6 servings.