To make ricotta filling, place ricotta, icing sugar, lemon zest and vanilla in a bowl and beat until well combined. Cover with plastic wrap and refrigerate for at least 1 hour to chill.
To make blueberry sauce, combine blueberries, caster sugar, lemon juice and cinnamon in a saucepan over medium heat and cook for 2-3 minutes until the berries release their juices. Combine arrowroot with 1 tbs cold water, then add to berry mixture. Cook until slightly thickened. Cool, then refrigerate until needed.
Preheat over to 180degrees C. Lay prepared crepes on a workbench, place a heaped tablespoonful of ricotta filling in centre of each crepe, fold in all four sides, then roll up to make parcels. Transfer to a baking tray, seam-side down, brush with melted butter, then bake for 20 minutes or until warmed through. Serve with sauce and dollops of creme fraiche.
Sift flour with a pinch of salt. Whisk the two eggs with 200mls of milk and 1/3 cup of water. Add to the flour gradually, whisking well to combine. Melt the butter and add 2 tbs to the batter. Brush a 20cm crepe or frypan with a little of the remaining melted butter and heat. Add 1/4c batter and swirl to coat base of pan. Cook 1 minute and flip. Don't worry if you have to discard the first crepe, it often happens. Keep going with the crepes placing each one between baking paper until needed. Makes about 10.