In a microwave safe bowl, add the butter and melt it for 30 seconds in the microwave.
3 (45g) Tbsp unsalted butter
In your stand mixing bowl or a large mixing bowl, add the active sourdough starter, whole milk, warm water (about 80 degrees), sugar, melted butter, and oil to the bowl of a stand mixer. Give everything a whisk, it's okay if it's still a little lumpy.
¾ (200g) cup active sourdough starter, ½ (120g) cup whole milk, ⅓ (80g) cup water, 1 (15g) Tbsp granulated white sugar, 2 (25g) Tbsp olive oil
Sourdough Discard Swap: If you want to make these without the active starter and use discard and yeast, add the discard and yeast to the wet ingredients above in place of the starter.
3/4 (200g) cup sourdough discard, 1 (4g) tsp instant yeast
After you combine the wet ingredients, add the all-purpose flour and salt to the bowl.
3⅓ (400g) cups all-purpose flour, 1½ (10g) tsp fine sea salt
Mixing by hand: If you're mixing this dough by hand, mix and knead the dough together until it's a smooth ball. This should take about 6-8 minutes.
Mixing with a stand mixer: If you're using a stand mixer, knead the dough on the lowest setting for 8-10 minutes, scraping the bowl halfway through to make sure everything is incorporated.
Once the dough is mixed, grease a bowl or container large enough for the dough to double with cooking spray and transfer the dough to the container. Cover the dough with plastic or a lint-free towel, and allow the dough to rest 30 minutes.