How to make
Beat the confectionery cream with a mixer to a thick cream. Add the sour cream. Beat until homogeneous.
Lay out a sheet of plastic wrap. Arrange 3 columns of 6 biscuits each, firmly next to each other. Smear on a layer of blueberry jam. Arrange a 2nd layer of biscuits on top. Smear generously with cream on top, then place washed and chopped strawberries.
Grab the wrap from both ends and lift up the side columns of biscuits. Form a roll. Smear it generously with cream. Sprinkle with grated white chocolate and garnish with strawberries.
Before cutting it, leave it for 3-4 hours in the fridge to set and for the biscuits to soften.