In order, place each ingredient for the crepes in a blender and blitz until smooth, about a minute. Scrape the sides of the blender and blend again until the batter is lump-free. Refrigerate for at least an hour (2 is ideal).
Preheat a nonstick skillet on medium to medium-high heat. Swirl some butter or oil in the pan and coat the bottom.
With the hot skillet in one hand and the batter in the other, slowly and steadily pour crepe batter into the center of the pan, tilting the skillet around to spread the batter evenly across the bottom in a very thin layer. It takes some practice but after 3 or 4 times, you can get consistently even crepes.
After 10-15 seconds, the crepe batter will look matte and the bottom should be lightly brown. Flip it over and cook another 10-15 seconds. Remove from pan and repeat this process until no more batter remains.
Using a butter knife or offset spatula, spread 2-3 tablespoons Nutella onto each crepe. Fold or roll up and top with powdered sugar. Serve with sliced fresh strawberries or roasted strawberries.
Roasted Strawberries
Preheat oven to 350 degrees F. On a large parchment-lined baking sheet, toss strawberries with sugar and vanilla.
Bake until caramelized and juicy, 28 to 30 minutes. Mash, if desired.