Mix sourdough starter with warm milk.
Add flour, sugar, and salt together.
Knead with your stand mixer attachment.
Add softened butter while kneading continues.
Knead for 8 minutes until smooth.
The dough should be soft and elastic.
Cover with a clean kitchen towel.
Let it rise for 4 hours.
Combine cream cheese in a bowl.
Mix in shredded cheddar cheese thoroughly.
Add diced jalapeños to the mixture.
Stir in crumbled bacon pieces completely.
Season with garlic powder and mix well.
Set aside until dough is ready.
Roll dough into a large rectangle.
Spread filling evenly over the surface.
Leave a small border around edges.
Roll tightly from the long side.
Cut into 12 equal pieces carefully.
Place rolls on prepared baking sheet.
Space them 2 inches apart evenly.
Cover rolls with a kitchen towel.
Let them rise for 2 hours.
They should look puffy and doubled.
Preheat your oven to 375°F now.
Brush rolls with beaten egg gently.
Bake for 25 to 30 minutes.
They should turn golden brown beautifully.
Remove when cheese bubbles appear visible.
Cool for 10 minutes before serving.