Combine Water and Starter: In a large mixing bowl, pour 450 g of water and add 150 g of sourdough starter. Stir until the starter dissolves.
Add Honey and Oil: Stir in 30 g of honey and 20 g of oil, mixing until fully incorporated.
Add Dry Ingredients: Add 400 g of spelt flour, 200 g of oats, and 15 g of salt to the bowl. Mix until the ingredients are combined and you have a rough, shaggy dough. Cover the bowl and let it rest for 4-5 hours
Transfer to a baking loaf lined with parchment paper
Let rise covered for 8-10 hours at room temperature
Sprinkle top with flour and oats
Bake at 420 for 30 to 40 minutes until well browned
Let cool and slice