Place all crêpe batter ingredients together in a blender. Blend until smooth. For best results refrigerate the batter for at least an hour before use.
Heat an 8-inch non-stick skillet or crêpe pan over medium heat. Lightly brush the inside of the pan with melted butter. (Pan will not need to be re-buttered unless crêpes start sticking.)
Pour a scant ¼-cup of batter into the pan. Quickly tilt and rotate the pan to evenly coat. Cook until the crêpe bottom is slightly browned. Loosen the edges with a silicone spatula as it cooks. Flip over when the batter is set. Cook on the second side for 10 to 20 seconds or until crêpe begins to brown. Transfer crêpe to a wire rack to cool, flipping so that the first side is down.
Repeat until batter is used up. Alternate stacking crêpes between 2 stacks on wire cooling rack. (Crêpes can be made ahead of time. Cooled crêpes can be stored in a food storage bag or sealed container for a couple of days.)
Melt butter in a large skillet over medium heat. Add garlic and cook until fragrant, about 30 seconds. Stir in artichoke hearts; season with salt and pepper. Cook until softened, about 3 minutes. Stir in spinach and cook until the liquid has cooked off, about 5 minutes. Reduce heat to medium-low; add cream cheese and heavy cream. Cook, stirring, until melted and smooth. Stir in parmesan and remove from heat.
To assemble, spread spinach artichoke filling over a quarter of the surface of a crepe and sprinkle with red pepper flakes. Fold in half, then in half again to form a triangle. Repeat with remaining crepes. Serve with extra grated parmesan.