Preheat oven to 325ºF. Prepare mega mini fluted pan with vegetable pan spray.
In large bowl, combine cake mix, pudding mix, water, oil, and eggs; beat at medium speed with electric mixer for 2 minutes. Gently stir in blueberries. Divide evenly among prepared pans; filling cavities about 2/3 full.
Bake 18-21 minutes or until toothpick inserted in center comes out clean. Cool in pan on cooling grid 5 minutes; remove from pan and cool completely.
For glaze, stir together confectioners’ sugar, milk, corn syrup and vanilla until smooth and well combined. Pour or pipe over cooled cakes.