Step 1

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

Step 2

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

Step 3

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

Step 4

Add prepared chicken breasts to the hot oil and cook for 3 minutes per side, or until just browned.

Step 5

Transfer chicken to slow cooker and top with mushrooms and garlic.

Step 6

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

Step 7

Pour wine over chicken and mushrooms.

Step 8

Close with a lid and cook on LOW for 4 to 5 hours, or on HIGH for 2 to 3 hours. Chicken is done when internal temperature reaches 165˚F.

Step 9

Remove chicken breasts from slow cooker and set aside on a plate.

Step 10

Combine water and cornstarch in a mug or a small mixing bowl and whisk until incorporated; then, whisk the slurry into the wine sauce.

Step 11

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

Step 12

Return chicken to the slow cooker; cover with a lid and cook on HIGH for 20 minutes, or until sauce has thickened.

Step 13

Transfer chicken from slow cooker to plates; top with mushroom sauce and garnish with fresh parsley.

Step 14

Serve.