Preheat oven to 400 degrees F. Line a 15x10x1-inch baking pan with parchment paper; set aside. In a large skillet cook bacon over medium heat until crisp. Remove bacon and drain on paper towels, reserving 2 tablespoons of the drippings. Crumble bacon; set aside.
Meanwhile, for crust, in a large bowl stir together muffin mix, flour, and the 2 teaspoons snipped or 1 teaspoon dried thyme. Using a fork, stir in egg and milk. Gather mixture into a ball, kneading gently until it holds together. Using floured hands, press dough into a 12x8-inch rectangle in the prepared baking pan.
Arrange pear slices on top of crust. Brush pear slices and crust with 1 to 2 tablespoons of the reserved bacon drippings.
Bake for 10 minutes. Sprinkle with blue cheese and crumbled bacon. Bake about 5 minutes more or until edges of crust are golden and center is set. If desired, sprinkle with walnuts and additional fresh thyme. Cut into rectangles.