Instructions for the Funfetti Brioche Dough

Cup of Yum
1. Begin by sprinkling the yeast and one teaspoon of sugar over the warmed milk. Stir this and set aside for 10 minutes until the yeast develops a good foam on top.
2. In the bowl of a stand mixer, fitted with a dough hook, place the flour, bread flour, salt and remaining sugar. Give this a quick stir.
3. Once the yeast is ready, pour this into the flour mixture immediately followed by two whole eggs and one egg white. Reserve the remaining egg yolk for an egg wash before baking.
4. Knead on a low speed for about 15 minutes until your dough is formed and is pulling itself from the sides of the bowl (see note).
5. Next, slowly add the butter a few bits at a time, while the mixer continues on a low setting.
6. Once all of the butter has been added, knead for about 7 or 8 minutes before adding the sprinkles. Then continue for about 7 or 8 minutes until the sprinkles have distributed within the dough and it is again pulling itself from the sides of the bowl.
7. Scrape the dough into a greased mixing bowl, cover with plastic wrap and place in the refrigerator to proof for about 8 hours (or overnight), during which time the dough should about double in size. (see note)

Instructions for Filling and Second Proof

1. Line a square baking pan with parchment paper and set aside.
2. In a small mixing bowl mash together the butter, sugar and cinnamon until you have a thick spreadable paste. This can usually be done with a spatula and doesn't require beaters.
3. Remove the dough from the refrigerator and scrape it out onto a well floured work surface. Press into into a rectangle using your hands, then roll out further with a rolling pin until you have a large rectangle about 12" wide by 15" long.
4. Spread your butter mixture over the surface of the dough, leaving a small gap around the edges. Then sprinkle over your rainbow sprinkles.
5. Roll the dough from the bottom to the top, forming a tight log.
6. Using flavorless dental floss or thin kitchen twine, trim the ends of your dough, removing an inch or two on each end of uneven and unfilled roll.
7. Mark out 9 roughly equal rolls from the remaining log and cut using the floss.
8. Place these in the lined baking pan and cover with a clean kitchen towel. Set aside at room temperature for about 2 hours or until doubled in size.

Instructions for Baking and Frosting

1. Preheat the oven to 350°F (175C/155C Fan) and prepare an egg wash (if using - see note).
2. Brush the rolls with the egg wash and bake in the preheated oven for about 25-30 minutes, until risen and golden brown.
3. Remove from the oven and allow to cool for about 10 minutes while you whisk up your frosting.
4. To make the frosting, stir together the powdered sugar, heavy cream and vanilla extract until smooth.
5. Spread this over the still warm rolls and then top with a generous coating of sprinkles (the measurement given here is just a guide - feel free to use less or more to your heart's content).
6. Serve while still meltingly soft and warm, either straight from the pan or use the parchment to remove and transfer to a serving plate.