Grease bottom and side of 10-inch angel food cake pan with shortening and lightly flour.
In small bowl, mix all Blackberry Filling ingredients and set aside.
In medium bowl, mix flour, baking powder and baking soda and set aside.
In large bowl, beat granulated sugar, butter, vanilla and eggs with electric mixer on medium speed for about 2 minutes, scraping bowl occasionally.
Beat in flour mixture alternately with sour cream on low speed.
Spread one-third of the batter in pan; sprinkle with half of the filling. Spoon another one-third of the batter by tablespoonfuls over filling. Sprinkle with remaining filling.
Spoon remaining batter over filling and spread it evenly.
Bake for 55 to 65 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes before removing from pan to wire rack.
Cool completely before glazing.
In a small bowl, stir all of the glaze ingredients until smooth and thin enough to drizzle. Drizzle over cooled coffee cake.
Recipe by Merry Christmas Recipes at https://merrychristmasrecipes.com/2013/07/25/blackberry-coffee-cake/