scoop the ice cream out on to a plate to help it soften evenly
while the ice cream is softening unroll your cake and get it ready to fill, wrap and freeze
once you can run a butter knife over it and it smooths over it's rime to roll
beginning on the short side of the roll, closest to the middle start adding an even layer of ice cream
leave about 1/2 inch gap on the two long sides, contiue carefully adding ice cream and making even until the whole cake roll is just about full
begin to roll it by gently rolling the cake around the ice cream, keep rolling, it may split a little bit but you'll be dusting it with powdered sugar so small splits won't matter too much
roll completely to the end, wipe off any excess filling
roll it firmly, cover with plastic wrap, put in the freezer where it can lay flat right on the bottom seam
freeze until ready serve, place on platter, dust with powdered sugar, slice while frozen
store any leftovers in the freezer