I don't really know what a mississippi mud pie is; the one time I went to eat one, they took way too long and we had to cancel the order to get where we needed to be on time. But, my friend in passing mentioned it was chocolate and coconut pie. I don't know if that's right, but it sounded pretty tasty. I've been thinking about it for a while; my plans had to change a bit on account of my lack of nuts and agave...
1/2 cup + 2 Tbsp macadamia nuts
1/2 cup + 2 Tbsp cashew nuts
1/4 cup + 1 Tbsp dates, pitted and packed (heaping cup)
21/2 tbsp cacao powder
meat of one young coconut
2 tbsp cacao powder
2 medjool dates or agave (or more, if you want it sweeter.)
coconut water, as needed
To make the crust, pulse the nuts in the food processor until crumbly. Add dates and cacao powder until well mixed. Use your fingers to form the crust in a tartlet pan. Put in fridge to firm up.
Blend all ingredients in a blender, adding coconut water until blends smoothly. Spoon into crusts and return to fridge to firm. I was impatient and ate mine after about 20 minutes and it was firm enough.