Combine the Swanson® Organic Free-Range Chicken Stock, beer, potatoes, onion, garlic, thyme sprigs, Parmesan, salt, and pepper in a 6-quart slow cooker. Cover and cook on LOW until vegetables are very soft, approximately 6-8 hours.
Remove and discard thyme sprigs. Add cream, and stir until combined.
Process soup using an immersion blender until smooth. (See notes for using a regular blender)
Just before serving, cook bacon in a non-stick skillet over medium heat until crisp, 6 to 8 minutes. Drain bacon using paper towels and reserve the drippings in pan.
Add the spinach to the skillet; increase heat to medium-high, and cook, stirring occasionally, until wilted and beginning to brown just around edges, about 3 minutes.
Crumble bacon. Serve soup topped with wilted spinach and bacon.