Add the cashews and pecans to a food processor. Process until a chunky meal as formed (not a flour). Next add the flax meal, maple syrup and vanilla. Process until the batter is smooth and begins to form a ball in the food processor. The batter should be sticky but can form a ball.
Place one sheet of parchment paper down on the counter, roll the batter into a ball (it will be sticky). Place it on the parchment paper. Then add a second piece of parchment paper on top of the dough. Using a rolling pin, begin to roll the dough into a circle shape (roughly 8 - 8 1/2 inches wide and long). Remove the top piece of parchment paper and then move the dough (still on the first piece of parchment paper) onto a baking sheet and place in the fridge for 30 minutes.
Meanwhile, prepare the filling. Add the dates and 1 tbsp of warm water to a clean food processor. Processor until small pieces of the dates remain. Melt the vegan butter over low heat in a saucepan. Next, add the rest of the filling ingredients (including the vegan butter) and blend. I would suggest adding 1 tbsp of cinnamon first, taste testing the filling and then adding the 1/2 tbsp if you feel it needs more. Set aside.
After 30 minutes, remove the dough from the fridge. Using a spoon, begin to coat the dough with the filling. The filling should be thick but spreads easy enough. Spread the filling evening to the outer edges of the dough. All the filling should be used up.
Very delicately, begin to tightly roll the dough up. Place back in the fridge for 1 hour. It can sit in the fridge for longer than 1 hour, but that is the minimum.
Prepare the vegan frosting. For option one, add the powdered sugar and milk into a clean food processor and blend until smooth. Or you can hand whisk. For option two, I found using hand beaters works best, but you can also whisk it by hand. Simply add the sugar, milk and butter altogether and whisk or beat until smooth. Set aside.
After 1 hour, remove the dough cylinder from the fridge. Cut the ends off (chef's treat) and then using a serrated knife, slice the dough into 7-8 cinnamon rolls. Top with the icing.
Store in the fridge (in a sealed container). And try not to eat them all in once sitting.