Crumble the cake into a medium sized bowl and add in the cream cheese. Finely crumble the cake into a large bowl. Add in a tablespoon of red food colouring and rub together till the cake turns pink or red as desired. Add in the vanilla essence and use the back of a large spoon to mix until thoroughly combined. Roll the mixture into 1 1/2 inch balls (if they aren’t moist enough to hold their shape, add a little more cream cheese) and place them on baking sheets. Place in the refrigerator 2 to 3 hours (or in the freezer 15 minutes). Meanwhile, melt down the white chocolate. When the balls have firmed up, dip the lollypop sticks into the chocolate and stick one into each ball. Put back into the fridge to firm for 5 minutes. Remove from the fridge when set and dip into the lollypops into the chocolate, dripping off any excess chocolate. Immediately sprinkle with coloured sprinkle, chocolate hearts or other decorations and allow to set.