From LA Times:
2 cups (8oz) cake flour
1 tsp baking powder
1/8 tsp salt
1 cup sugar
1/2 cup plus 6 tbsp softened butter
3 egg yolks
juice and finely grated zest of 1 orange
2 heaping tbsp orange marmalade
1 tbsp vanilla
garnishes: mascarpone and heavy cream whipped together, candied orange peel
Heat oven to 350F. Lightly grease and flour a 9″ Bundt pan. In bowl of stand mixer, whisk flour, baking powder, salt, and sugar. Add butter and mix using paddle attachment, until butter fully incorporated.
In separate bowl, beat yolks, juice and zest, marmalade, and vanilla. With mixer running, slowly beat in half the egg mixture until incorporated, then beat in the second half.
Spoon batter into pan and bake till puffed and lightly browned, and toothpick in center comes out clean (50-60min). Rotate halfway through for even coloring. Cool on a rack.