CHICKEN PESTO: Season chicken on both sides with salt and pepper. Place chicken into the bottom of a slow cooker. Spread pesto over the top of the chicken. Drizzle with lemon juice. Slice butter into 8 tablespoons and lay over the chicken and pesto.
Cover and cook on LOW for 5-6 hours.
PASTA: During the last 10 minutes of cooking, boil pasta according to package directions for al dente about 7-8 minutes; drain well.
Shred chicken in the slow cooker with 2 forks. Add the cooked pasta and parmesan cheese, stir everything together until pasta is coated with the buttery pesto sauce and the chicken is evenly dispersed throughout the pasta.
Top with shredded mozzarella cheese. Cover and cook for 10-15 minutes more or until the cheese has melted.
Garnish with dried basil. Serve in pasta bowls and enjoy!