1. Pulse the avocados in your food processor until there are few chunks left. Pulse in the cacao powder, syrup, vanilla and salt.
2. Keep blending until the mixture is completely fluffy and smooth. Scoop the mixture into an airtight glass container and freeze overnight. Before assembling your sandwiches, you may need the ice cream to sit out at room temperature for a few minutes, to soften.
3. Cut your Rickaroons in half, lengthwise. To assemble each one, place one ‘Roon half on a plate, place a scoop of ice cream on top, then place the other ‘Roon half on top of that. Slightly flatten the sandwich down with your hand. Repeat with other ‘Roons. Serve and enjoy!