In a stand mixer bowl, combine warm milk, 1 tablespoon of sugar, and yeast. Let it sit until foamy, about 5 minutes.

Add the beaten eggs, softened butter, remaining sugar, all-purpose flour, bread flour, and salt to the yeast mixture. Knead with the dough hook for 5 minutes until smooth and elastic.

Grease a large bowl, place the dough inside, and cover it with a kitchen towel. Let it rise in a warm place until doubled in size, about 1-2 hours.

In a small bowl, mix softened butter, brown sugar, granulated sugar, flour, vanilla, and salt until combined.

Once the dough has risen, punch it down and roll it out on a floured surface into a large rectangle. Spread the filling evenly, sprinkle with rainbow sprinkles, and tightly roll the dough to form a log.

Using a sharp knife or dental floss, cut the log into 9 equal-sized rolls and place in a greased baking dish. Cover and let rise until doubled, about 1 hour.

Preheat your oven to 325°F (163°C) and bake the rolls for 35-40 minutes until golden brown.

For the frosting, beat together cream cheese, softened butter, confectioners’ sugar, vanilla, and salt until smooth. Spread the frosting over warm rolls and sprinkle with additional rainbow sprinkles for that birthday celebration feel.