2 cups firmly packed brown sugar
3 cups all-purpose flour
2 teaspoons baking powder
1/2 teaspoon ground cinnamon
1/2 teaspoon ground ginger
1/2 cup sour cream
1/2 cup seedless blackberry jam or spreadable fruit preserves
1 cup powdered sugar
1/2 teaspoon vanilla
1 to 2 tablespoons milk
Fresh blackberries, if desired
Heat oven to 350°F. Grease and flour 12-cup Bundt® pan.
Combine brown sugar and butter in bowl; beat at medium speed until light and fluffy. Add 1 egg at a time, beating well after each addition.
Combine flour, baking powder, cinnamon and ginger in another bowl. Alternately add flour mixture and sour cream to butter mixture. Beat until smooth and well mixed.
Spoon half of cake batter into prepared pan. Spoon jam over cake batter to within 1/4 inch from sides of pan; lightly swirl into batter with knife. Top with remaining cake batter, spreading evenly over top of jam. Bake 50-55 minutes or until toothpick inserted in center comes out clean. Cool 15 minutes; remove from pan. Cool completely.
Combine powdered sugar, vanilla and enough milk for desired glazing consistency in bowl; mix well. Drizzle over cake. Serve cake with fresh blackberries, if desired.
For a flavor variation, use seedless raspberry jam.