First set the oven to 180C/ 350F. Line a 10in x 7 in or 325cm x 17cm rectangular tin with high sides or a brownie tin
Put the coconut, cocoa, almonds, oats or almond meal and dates into the food processor and blitz till fine . Add the coconut or melted butter and combine again. The mixture looks a little dry
Press onto the bottom of the tin and bake for 15-20 minutes or until starting to go golden around the edges. Cool slightly then chill or freeze for up to 1 hour . The filling can be made and left till the base is ready.
To make the filling soften the cashews by either simmering or soaking. Put the dates into a pot with the water. Simmer on low till the dates start to get soft. Mix them and they will turn into a purée. Cool. Add the dates, cashews maple syrup, vanilla and {butter or) coconut oil, into the processor and blend, scraping down the sides and blitzing again until very smooth
Spread this over the nut base and even out with a pallet knife, or put a piece of plastic over the top and smooth down with your hands. Refrigerate for as long as possible.
To make the chocolate icing. Melt the coconut milk till hot. Put the chocolate pieces into a ceramic bowl and pour the coconut cream over the top Stir till melted. If it needs a little more melting put in the microwave for 20 seconds. Stir again. Spread onto the slice with a pallet or knife,
Slice with a hot knife and Keep chilled.