my old roommate,
julia and i used to always make this recipe for birthdays. i haven't made it in a while and i decided to make it for a friend's birthday–but a little bit more fancy. i even added a sort of frosting to drizzle on top.
1 cup fat-free sour cream
3/4 cup plus 1 Tbsp. warm water
3 Tbsp. vegetable oil
4 eggs, one at a time
1 (18.25-oz.) package devil's food cake mix (we normally would use a yellow cake mix for a less rich cake)
1 (3.9-oz.) package chocolate instant pudding mix
1/2 cup semisweet chocolate chips (i'm pretty sure what i put in was more than that)
Coat a 12-cup bundt pan with cooking spray and dust with flour; set aside. Combine the sour cream and next six ingredients (sour cream through chocolate pudding mix) in a large bowl, and beat mixture at medium speed of a mixer for three minutes. Add the chocolate chips and beat the mixture for 30 seconds. Spoon the cake batter into the prepared bundt pan. Bake cake at 350º for an hour or until a wooden pick inserted in center comes out clean. Cool cake in pan 10 minutes on a wire rack. Invert cake onto a wire rack and cool completely.

then i made up a frosting that sorta went like this:
2 T. melted butter
1 (8 oz.) pkg. low fat cream cheese
powdered sugar to taste (maybe 1/2 c.?)

et voila! birthday bundt cake–fancified.