Step 1

Preheat oven to 350°. Grease and flour a 10-in. fluted tube pan. In a large bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Add eggs, 1 at a time, beating well after each addition. Beat in orange zest and vanilla. Combine flour, baking powder and salt; add to creamed mixture alternately with sour cream. Fold in cranberries. Pour into prepared pan.

Step 2

Bake until a toothpick inserted in the center comes out clean, 65-70 minutes. Cool for 10 minutes before removing from pan to a wire rack to cool completely.

Step 3

For the vanilla butter sauce, in a small saucepan, combine sugar and flour. Stir in cream and butter; bring to a boil over medium heat, stirring constantly. Boil for 2 minutes. Remove from the heat and stir in vanilla. Serve warm over cake.