1/3cup+ 3 tablespoons butter (cold and cut into small pieces)(110 grams)
Pre-heat oven to 350° (180° celsius). Grease and flour an 8-9 inch (depending how thick you like your base, I used a 9 inch for this one) cake pan (20-24 centimeter). A spring form pan is my recommendation.
In a large bowl whisk together the flour, sugar, baking powder and salt, add butter, using a pastry blender or fork combine to form a coarse crumb mixture, add the egg and continue to mix only until still crumbly.
Place approximately 2/3 of the crumbly mixture in the cake pan, lightly pat down. Spread the Nutella* evenly on top and sprinkle with remaining crumb mixture.
Bake for approximately 30-40 minutes or until lightly golden on top. Let cool. Enjoy!
*If the Nutella is hard, place in a small plate and over a pot of boiling water stir until smooth and soft.