Cream sugar and butter until fluffy, about 5 minutes. Add egg and vanilla.
Mix dry ingredients in separate bowl and add to butter mixture, mix well. Separate the dough in five equal piece.
Color the dough so you end up with one yellow, red, purple, green and blue piece.
Put one of the freshly made dough between two sheets of parchment paper and roll 11 x 9 inches and 1/8 inch thick. Repeat with the other color dough.
Put the rolled dough including the parchment paper, on a cookie sheet and refrigerate for 10 minutes or longer. - you can NOT skip this step!
Take the top layer off both dough’s and lightly wet the tops with water and your fingers.
Sandwich the colors together, using a paring knife trim the edges to make straight edges.
Remove the top layer of paper and start rolling up and use the bottom layer of paper to pull it tight. If the dough tears you can just pinch it together.
Poor the sprinkles onto a large platter and roll the log onto the sprinkles and press them in.
Place the dough into the fridge for 15 minutes or longer. - Do NOT Skip this step!
Then slice the dough into 1/4 inch slices and bake on parchment lined sheets. Bake at 325° F for 10 -15 minutes.