In an electric mixer fitted with a paddle attachment, combine butter and sugars until combined.
Add imitation vanilla. Mix until combined.
Add flour. Mix until just combined.
Stir in sprinkles and white chocolate chips.
Scoop out 1 heaping tablespoon of dough. Sandwich it between two pretzels. Repeat with the rest of the dough.
Place sandwiches in the fridge for 15 minutes.
While the pretzels are in the fridge, melt 10 oz of white chocolate in 30 second increments.
Once it is melted, color the chocolate desired color. (If you want half purple and half pink, divide the chocolate in half before coloring).
Set up a piece of parchment paper on a flat surface.
Take the pretzel sandwiches out of the fridge. Dip each one half way into the chocolate.
Place them on parchment paper and immediately add sprinkles.