Ingredients:
1/2 cup (1 stick) unsalted butter, softened to room temperature (you want the butter quite soft)
1 1/3 cups granulated white sugar
¼ cup cocoa powder, sifted
1 teaspoon pure vanilla extract
¼ teaspoon salt
2 large eggs, room temperature
½ cup all-purpose flour

Directions:
Preheat the oven to 350 degrees and position rack in the lower third of the oven. Use a flour-based cooking spray (like Baker’s Joy or Pam with Flour) to liberally grease an 8-inch kladdkaka pan or round cake pan, coating the bottom and sides.

Use a stand or handheld mixer to beat the butter on medium-high speed until very soft and peaks form, about 1 minute. Use a rubber spatula to scrape the sides and bottom of the bowl.

Add the sugar, sifted cocoa powder, vanilla and salt. Beat on medium speed until well combined, about 1 minute. Scrape the bottom and sides of the bowl again and add the eggs. Beat on medium speed until smooth and fully incorporated, about 1 minute. Add the flour and mix on low speed until combined, about 30 seconds.

Spoon the batter into the prepared pan – it will be very thick. Use the back of the spoon or a spatula to evenly spread the batter into the pan and smooth the surface.

Bake the cake in the lower third of the oven for about 25 to 30 minutes. The center will crack and puff up, and then a minute or so later it will start to fall – this is the time to remove it.  The toothpick test will not work for this recipe as the center is supposed to be thick and gooey when done. Transfer to a wire rack and let cool for 20 minutes.

Use an offset spatula or knife to gently release the cake along the edges of the pan as needed. Place a plate or cake board over the top of the pan and invert it – you may need to tap the plate firmly on a hard surface to release the cake. Let the cake cool completely before serving.

To serve: Dust the top and sides with powdered sugar, if desired, or top with fresh berries. Serve plain or with fresh fruit, whipped cream or ice cream.

To store: Wrap the cake in plastic wrap and store in an airtight container at room temperature for 3 to 4 days or in the freezer for up to 2 months. To freeze individual portions, cut the cake into wedges and freeze them for 1 hour until firm and easy to handle. Wrap each wedge in plastic and place in a plastic freezer bag. Allow the cake to thaw completely at room temperature before unwrapping and serving.