Preheat oven to 400F/200C/gas mark 6. Lightly grease muffins tins with the butter wrapper.
Using long pulses, blend flour, butter, and cream cheese in food processor until it comes together in a ball.
Knead lightly just a few times with your floured hands.
Roll out on a board dusted with fine white rice flour to ⅛" (3 mm) thick. Use just enough flour on your hands, the board, your rolling pin, and the cutter to keep the dough from sticking.
Cut with a floured glass that is just slightly larger than the diameter of the muffin tin at the top opening. Use a metal spatula or bench scraper to pick up each circle of dough.
Gently press each circle into the muffin tins.
Bake 5 minutes, then remove to add the filling.
Blend berries with berry spread and 2 tbsp (30 ml) filtered water until very smooth.
Spoon about ½ tbsp into regular-sized tarts, 1 tsp into tartlets, distributing fill evenly among the tarts.
Bake another 5-8 minutes until golden brown.
Cool on wire racks.
Loosen tarts with a butter knife or small offset spatula to remove from pan.
