Soak cashews and dates in separate bowls, using enough HOT water to cover, for 15 minutes. Drain.
Blend up the almonds and put them in a small bowl. Blend the dates and add them to the almonds, then mix until you have a crumbly dough. Divide mixture between 12 lined muffin tins or 6 lined Texas muffin tins, pressing into the bottom of the pan.
Blend cashews, margaine, lemon juice, water, maple syrup, and vanilla until very smooth. This might take longer than you think – keep blending and testing until you have a totally smooth mixture that’s not grainy at all. Pour the mixture into the muffin pan, filling each cup completely. Top with the berries, if you’re using them.