Preheat your oven to 180C/350F and grease a springform cake tin and place 2 teaspoons flour into the tin.
Tap and swirl the tin to coat fully and upturn to discard any excess flour. Set aside.
Place the butter and chocolate into a saucepan on low heat, stirring to melt evenly. Set aside.
Place the eggs and sugar into a bowl and whisk to combine until lightly frothy.
Sift the flour therein and whisk to combine until smooth.
Pour in the warm chocolate and butter and whisk to combine until smooth.
Pour into your cake tin and tap lightly smooth.
Bake for 25 minutes or the cake is lightly risen and beginning to go golden at the edges.
Remove and allow to cool for 5 minutes in the cake tin.
Remove from the cake tin and allow to cool fully.
Slice and serve with a dollop of yogurt or whipped cream and your favorite hot beverage.
Enjoy!
Video
Notes
Dark chocolate: 54% dark chocolate was used thanks to it's overall higher quality. If you prefer, you could replace with milk chocolate in equal measure, though the final result will likely be a lot sweeter.
Sugar: The best sugar here is superfine or caster which helps dissolve into the eggs and remaining cake batter. You could half and half the sugar with raw sugar or light brown sugar and caster sugar as I do not recommend completely substituting out superfine or caster sugar.
Springform cake tin: A springform tin makes getting the cake out of the tin easy work! This is best baked in a 20cm or 8 inch tin or smaller for a cake that isn't too flat.
You can make this ahead: Best served within 2 days of baking, this will last up to 4 days when kept covered in a container.