My mom has been making this cake for years.

3 eggs
1 cup sugar
1 cup vegetable oil
1 cup plain yogurt
1 3/4 cup flour
1 teaspoon baking powder
1 teaspoon baking soda
1 tablespoon orange rind finely chopped

beat eggs in a stand up mixer for a few minutes add sugar, oil and plain yogurt, beat well, add flour, baking powder and baking soda, add orange rind.

make the filling

1/3 cup sugar
2 tablespoons baking cocoa
2-3 teaspoons cinnamon

make the glaze

1/3 cup concentrated orange juice
1/3 cup sugar

Spoon 1/3 of the batter in a bundt pan that is sprayed with Pam, alternated with the cinnamon mixture, marble gently with a knife.
bake at 325 for 50 minutes
brush on glaze while warm.
enjoy!