1. In the bowl of your stand mixer, combine yeast, water, and sugar and allow to sit for 15 minutes.
2. Meanwhile, cut two rounds of parchment paper to fit in the bottom of 2 8-inch round cake pans. Place the parchment in the pans and spray with non-stick cooking spray.
3. Prepare the filling mixture by tossing blueberries and raspberries in a bowl with sugar and cornstarch until coated. Set aside.
4. Preheat the oven to 400 degrees.
5. Add salt and butter to the yeast mixture in the stand mixer. Mix with a dough hook and add flour ½ cup at a time until a soft dough forms. Add more flour if needed. Dough should be tacky, but not sticky.
6. Turn out the dough onto a lightly floured surface and divide into two pieces. Roll out each piece into a 9x11 rectangle.
7. Spread half of the berry mixture ½ inch from one edge, lengthwise. Pull the border over the berry mixture and keep rolling dough up tightly. Repeat with remaining dough.
8. Slice each log into 6-8 evenly sized rolls and place in the prepared baking pans. Let rest for 5 minutes.
9. Bake for 15-18 minutes or until the tops of the rolls are golden.
10. Remove from the oven and place pans on a wire rack.
11. Prepare the glaze by combining the cream cheese and powdered sugar together in the bowl of a stand mixer and mixing on low speed until fully combined. Add in milk a little at a time until the glaze reaches a consistency where it can be poured over the rolls.
12. Pour glaze over the rolls and enjoy warm. Uneaten rolls can be refrigerated for 2-3 days if covered. Reheat by microwaving in 30 second intervals. Additional glaze may need to be added if rolls are dry.