In a medium bowl, whisk together the eggs, milk and vanilla until well combined. Set aside.
Spread Nutella on each of 8 slices of bread. Roll each bread slice into a cigar shape with the Nutella filling on the inside.
Dip each bread roll into the egg mixture and place into a baking dish, seam side down. Continue with the remaining bread rolls, placing them side-by-side in the baking dish, enchilada-style. Pour the remaining custard over the top of the bread.
Refrigerate for at least 2 hours or overnight, until the custard has been absorbed by the bread.
Preheat the oven to 375 degrees. Then bake for 30-35 minutes until the tops are golden brown. Dust some powdered sugar over the top with a sifter, and drizzle with a little melted Nutella if you wish. Serve with sliced strawberries and maple syrup, if desired. ENJOY!