Here are two sour cream coffee cakes I have, just in case Pat doesn't answer.Both of them. I would suppose, should be moist, judging from the ingredients.

Sour Cream Coffee Cake

Cream together:
1 1/2 c. sugar
1 c. Crisco Oil
4 eggs
Add:
2 t. vanilla
1/2 pint (1 cup) sour cream
Sift together and add:
2 1/4 c. flour
1/2 teaspoon salt
1 teaspoon soda
1 teaspoon baking powder
Topping:
1/2 c. chopped nuts
1/2 c. brown sugar, firmly packed
2 t. cinnamon

Layer batter and topping—half and half of each—in greased tube pan. Bake at 350F. for 1 hour.

Sour Cream Coffee Cake

1/4 cup firmly packed brown sugar
2 teaspoons ground cinnamon
1 cup chopped pecans, divided
1 (18 1/2-ounce) package yellow cake mix
3/4 cup salad oil
1/2 cup sugar
1 teaspoon vanilla extract
4 eggs
1 cup commercial sour cream

Grease and flour a 10-inch tube or Bundt pan. Combine brown sugar, cinnamon and 1/2 cup pecans; set aside.

Combine cake mix, salad oil, sugar, vanilla, eggs. and sour cream; beat exactly 2 minutes at medium speed of an electric mixer. Stir in 1/2 cup pecans. Pour half of batter into prepared pan; sprinkle brown sugar mixture over batter. Pour remaining batter into pan.

Bake at 325º for 50 to 60 minutes. Allow cake to cool in pan 30 minutes before turning out.
Yield: one 10-inch cake.
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Judging from Pat's recipe directions, I would think there might be two kinds of sugars. Just a guess.