Get 6 oz ramekins and spray them with cooking spray to avoid the chocolate lava cake sticking on their surface. Set the oven on 425 F degrees.
Fill a heat-proof bowl with butter. Top it off with the chocolate, which should be chopped. Place it in the microwave and wait for it to melt. Stir it often when you check it.
Grab a bowl and mix the sugar, salt, and flour. Include the eggs, egg yolks, whisk them very well. Combine the bowl with flour and eggs together with the bowl of chocolate. Mix the batter with a spatula and make sure to remove all lumps.
Fill all the ramekins with the mixture.
Put the ramekins on a baking sheet and put them in the oven for around 14 minutes. The chocolate lava cake will be ready when the top is only a little bit soft.
Serve them right away. They are best served with vanilla icecream.