In a large mixing bowl, combine 3.5 cups of all-purpose flour, instant dry yeast, and fine salt. Use a whisk to blend the dry ingredients together.

In a saucepan, heat 1 cup of whole milk, 1/3 cup of unsalted butter, and 1/4 cup of granulated sugar over medium heat until it's warm but not boiling, about 5 minutes.

Pour the warm milk mixture into the bowl with the dry ingredients. Stir until combined, then add 1 large room temperature egg. Mix until a dough forms, adjusting with additional flour as needed until the dough is elastic and slightly tacky to the touch.

Cover the dough with a clean kitchen towel and let it rest in a warm area for 10 minutes.

Lightly flour your countertop and roll out the rested dough into a rectangle measuring approximately 12x18 inches. Aim for even thickness.

Sprinkle half of the rainbow sprinkles evenly over the dough and gently fold it in half lengthwise. Roll out the dough again, pressing in the remaining sprinkles.

Brush the rolled-out dough with melted unsalted butter (about 1/4 cup), then mix 1/2 cup of light brown sugar with 2 tablespoons of ground cinnamon and spread this mixture evenly over the dough.

Starting from one long edge, carefully roll the dough tightly into a log shape. Pinch the seam to seal it closed.

Using unflavored dental floss, cut the log into 9 equally sized pieces. Place each piece into a greased baking pan, cut side up.

Cover the pan with foil and allow the rolls to rise for 30 minutes.

Preheat your oven to 350°F (175°C). Once warmed, remove the foil and bake the Funfetti Cinnamon Rolls for 26-32 minutes.

While the rolls bake, make the frosting by whipping together 1/4 cup of unsalted butter, 1 teaspoon of vanilla extract, 1/4 teaspoon of almond extract, and a pinch of fine salt. Gradually add 2 cups of powdered sugar, mixing until smooth.

Let the rolls cool for 10-20 minutes before applying the frosting generously.