Prepare vegetables by peeling and dicing them in chunks.
Add the vegetables into the crockpot with olive oil.
Cook on HIGH for 4 hours.
While the vegetables are cooking, make the sage brown butter: Melt butter in a pan over medium heat. Add sage leaves and cook until butter is browned and fragrant. Remove from heat.
After 4 hours, blend the soup mixture with an immersion blender or in a regular blender until smooth.
Strain the butternut squash mixture in a separate pot until it’s smooth and creamy.
Stir in the sage-infused brown butter, salt, maple syrup, and apple cider vinegar.
Top with sour cream and pumpkin seeds (optional).