There are as many conflicting ideas on how to eat this cake as there are recipes for it. Some like it warm with ice cream, some like it at room temperature with nothing, and I like it as my wife will tell you to eat it: cold from the refrigerator with whipped cream on the side." 

Swedish Gooey Chocolate Cake

Ingredients

• 200grams (7-ounces or 1 3/4 sticks) butter, plus extra to grease
• Breadcrumbs, to coat
• 200grams (7-ounces) dark (semisweet) chocolate, broken into small pieces
• 4eggs
• 250grams (9-ounces or 1 1/4 cups) sugar
• 40grams (1 1/2-ounces or 1/3 cup) weak (soft) wheat flour
• Good pinch of sea salt

Directions

1. Preheat the oven to 175ºC/345ºF/Gas Mark 4. Butter a 24-cm/9 1/2-inch springform cake pan and coat with breadcrumbs.
2. Melt the butter in a medium pan over a low heat. Add the chocolate and keep melting everything together while stirring. Remove the pan from the heat and add the rest of the ingredients while you keep stirring until well combined.
3. Scrape the batter into the prepared cake pan, smooth the surface and bake for 15 to 20 minutes. It should be sticky on the inside. If the cake gets too dark, cover it with aluminum foil for the last 5 minutes.

https://food52.com/recipes/78276-the-nordic-baking-book-s-kladdkaka-swedish-gooey-chocolate-cake