Preheat the oven to 400 degrees. Using a food processor, grind the pecans into fine crumbs. Transfer to a wide, shallow bowl and stir in the bread crumbs and basil. Season with salt and pepper. Rub each chicken breast with honey mustard, then coat with the pecan mixture. Place on a nonstick baking sheet and drizzle with 2 tablespoons olive oil. Bake until the juices run clear, 15 to 20 minutes.