Add 4 tbsp of butter to a large dutch oven or stock pot. Let it melt over medium-high heat.
Now add the onion and carrots. Cook for about 1 minute. Now toss in the yellow squash and stir. Cook with the lid on for about 8 minutes, stirring occasionally.
Add the garlic powder, curry powder, cumin, thyme sprigs and lemon juice (be careful to not add too much lemon juice). Stir and cook for 60 seconds.
Add 2 tbsp of white wine to deglaze the pan and stir, scraping up any brown bits from the bottom of the pan. Let the wine cook for 60 seconds over high heat with the lid off to cook off the alcohol flavor.
Now add the 3 cups of chicken broth and salt. Let the soup simmer on low for about 10 minutes to combine all of the flavors. Once done, remove from heat and let it sit for 15 minutes to cool down.
Remove the thyme sprigs. The thyme leaves should have fallen off into the soup.
Using your immersion blender or blender, blend the ingredients of the soup until you have a smooth consistency, and there are no chunks of squash left.
Pour in the heavy cream and 1 more tbsp of butter, and stir to fully combine.
Serve immediately, or refrigerate and enjoy it the next day! You can also freeze this soup for a nice summer squash soup in the winter months. Option to garnish with nuts, thyme, parsley, green onion or peppers! Enjoy!