Put the plain flour, cocoa powder, salt and sugar in a large mixing bowl, make a well in the centre and add the eggs. Start stirring with a balloon whisk, then slowly whisk in the melted butter, milk and water. Increase your whisking speed until you have a thin batter about the consistency of single cream.
Next, heat a frying pan (preferably non-stick) over a medium heat, drizzle in a teaspoon of melted butter and wipe it over the base with kitchen paper.
Drop a small ladleful of pancake batter into the pan, swirling so it coats the base evenly in a thin layer. Cook for 2 minutes or until the underside is golden, then flip and cook on the other side for a minute or so. Remove to a warm plate and repeat.
Stack the crêpes between layers of baking parchment as you go, keeping them warm in a low oven.
Serve warm with generous spoonfuls of Bonne Maman Hazelnut Chocolate Spread.