Ciabatta?

Knäckebröd for reference(so you know the size danskjävel!) I let it proof for 24hr(ish) in the fridge then added baking powder let it proof again in 30ish celsius for 6 hours and then into the oven. Sadly my oven only goes to 250 but it went fine anyways

Crumb turned out alright although I had to use baking powder instead of bakers yeast.

The flour I used.
The final result was real nice although I didn’t follow your recipe completely