Fresh Blueberry Coffee Cake

1 1/4 c. fresh blueberries
1 1/3 c. white sugar, divided
2 Tbsp cornstarch
1/2 c. butter, softened
2 eggs
2 c. flour
1/2 tsp salt
1 tsp baking powder
1 c. sour cream
1 tsp vanilla or almond extract
1/2 c. pecans (optional)
3/4 c. powdered sugar
1 Tbsp warm water
1 tsp vanilla or almond extract
1. Preheat oven to 350 degrees F. Grease tube pan.
2. In a small saucepan, combine blueberries, 1/3 cup sugar and cornstarch. Cook over medium heat 2-3 minutes, or until thick. Stir constantly and set aside.
3. Cream butter and sugar. Add eggs one at a time, beating well after each.
4. Combine flour, salt and baking powder. Add to creamed mixture alternately with sour cream. Add flavoring.
5. Spoon half of mixture into prepared pan. Spoon half of blueberry mixture into pan. Add remaining batter, then blueberries. Swirl with a knife gently. Sprinkle with pecans, if using.
6. Bake 50 minutes. Let stand 5 minutes before removing from pan. Place on a serving dish.
7. Prepare glaze: Mix glaze ingredients well. Drizzle over top of cake.