1/3 cup packed dark brown sugar
2 teaspoons unsweetened cocoa powder
1/3 cup chopped semisweet chocolate
1 teaspoon ground cinnamon
1/3 cup raisins
1/3 cup golden raisins
1/2 cup toasted walnuts, chopped

3/4 cup unsalted butter
1/2 (8 ounce) package cream cheese
1 cup packed brown sugar
1/3 cup white sugar
5 eggs
1 1/2 teaspoons vanilla extract
1 cup plain yogurt
3 1/4 cups all-purpose flour
1/4 teaspoon salt
1 tablespoon baking powder
1/2 teaspoon baking soda