1) Cover a baking sheet with clingfilm or foil. Using a serrated knife, cut ice cream package in half lengthwise through the cardboard. Wrap one half in clingfilm and freeze for another use. Halve the remaining piece lengthwise. Flip the ice cream, with the 2 pieces still together, so the cut side is up, and cut it crosswise into 4 equal sections, you'll have 8 pieces of ice cream.
2) Place a crepe on the work surface and place a piece of ice cream in the center. Fold the crepe over the ice cream to enclose completely. Place the filled crepes on the prepared baking sheet. Continue with the remaining ice cream and crepes and freeze until just firm. (This recipe can be prepared up to this point 1 day in advance. Wrap carefully in clingfilm before freezing. Allow to soften slightly before proceeding.)
3) Peel and slice the bananas on a sharp angle into 5-cm pieces. Melt the butter in a large skillet over medium heat. Add the granulated sugar, brown sugar, cinnamon, nutmeg and lemon juice and cook, stirring, until smooth and just at a simmer, about 3 mins. Remove skillet from heat and add orange liqueur. Return skillet to high heat and stir until smooth. Carefully fold in bananas. Remove the skillet from heat and add the rum. Return the skillet to the heat, and shake the pan back and forth to warm the rum and coat the bananas. (If working over a gas flame the sauce may ignite; continue to cook until the flames subside.)
4) To serve, place 2 filled crepes on a plate crisscrossing each other and spoon banana mixture over the top. Garnish with sifted icing sugar and a sprig of mint, if desired.
For the crepes:
140g plain flour
25g granulated sugar
Pinch of salt
3 large eggs
5ml pure vanilla essence
60g unsalted butter, melted
1) Whisk the flour, sugar, and salt together in a bowl. Gradually whisk in the milk, water, eggs and vanilla essence, and continue whisking until smooth. (The batter can be made to this point a day ahead and refrigerated. Bring to room temperature before adding the butter.) Stir in the butter. Set aside for at least 30 mins to rest. (The crepe batter may be made in a food processor blender: Pulse the dry ingredients, then add the wet, process until smooth, and then stir in the butter.) Pour the batter into measuring cup with a spout.
2) Have a plate near the stove to stack the cooked crepes, or 4 plates, if you plan to serve the crepes immediately. Heat a medium nonstick skillet over medium heat until a drop of water bounces and sizzles briefly around the pan before evaporating. Pour a scant 60ml of batter into the skillet and quickly swirl it to coat the pan evenly. Cook until the batter sets, about 1 to 1.5 mins. The crepe will blister in the middle, and the edges will look dry and slightly crispy. Using your fingers or a spatula, carefully pick the crepe up by its edges and flip it over to cook the other side, about 15 to 30 secs. Repeat with the rest of the batter, stacking the crepes on the plate as you go.