Preheat the oven to 150 °C.

Place dark chocolate chips, butter and oil in a bowl and melt it over double boiler.

Take the chocolate mixture off the double boiler and allow to come down from hot to warm temperature.

In a mixing bowl, add eggs and sugar. Whisk until well combined. No need to make froth.

Add the chocolate mixture and mix again.

Lastly, add all purpose flour and mix until well combined.

Line a 20 x 20 cm square baking tin with a parchment paper and pour the mixture in it.

Bake at 150 °C for 20 minutes (soft and super moist texture).

Bake at 160 °C for 20 minutes (crispier texture).

Allow to cool and frost with Nutella.

Enjoy with tea or coffee!