In a large bowl, whisk cake mix, flour and sugar. Stir in melted butter, vanilla, milk and sprinkles. Mixture should be moist and be able to hold its shape easily when formed. Using a cookie scoop, form mixture into even balls and refrigerate 20-30 minutes.

In the mean time, melt chocolate in a double boiler or slowly in the microwave. Using a fork, drop one of the cake batter truffles into the chocolate and roll around to coat. Tap off the excess gently and transfer to cookie sheet lined with wax paper. Top with more sprinkles, if desired.