Step 1

Lightly grease a 6-quart slow cooker with cooking spray.

Step 2

Season the chicken breasts all around with the garlic powder, the dried basil, the thyme, the paprika, the salt, and the pepper.

Step 3

Heat the olive oil in a skillet over medium-high heat.

Step 4

Add the prepared chicken breasts to the hot oil and cook until they are just browned, about 3 minutes per side.

Step 5

Transfer the chicken to the slow cooker and top it with the mushrooms and the minced garlic.

Step 6

Return the skillet over medium-high heat, add the marsala wine, and cook, while scraping up all the browned bits from the bottom of the skillet, for 1 minute.

Step 7

Pour the heated wine over the chicken and the mushrooms.

Step 8

Place the lid on the slow cooker and cook until the chicken reaches an internal temperature of 165 degrees F, about 4-5 hours on low heat and 2-3 hours on high heat.

Step 9

Transfer the cooked chicken breasts from the slow cooker.

Step 10

Combine the water and the cornstarch in a mug or a small mixing bowl and whisk until incorporated.

Step 11

Add the cornstarch mixture to the wine sauce and whisk to combine.

Step 12

Add the heavy cream to the wine sauce and whisk until combined.

Step 13

Return the chicken to the slow cooker and cover with the lid and cook on high heat until the sauce is thickened, about 20 minutes.

Step 14

Serve the chicken and the mushroom sauce garnished with the parsley.