Marinate the chicken. Trim the chicken of any extra fat, cut into chunks, and place it in a gallon freezer bag or shallow bowl. Whisk the balsamic vinegar, 2 tablespoons of olive oil, brown sugar, and soy sauce in a bowl. Pour the marinade over the chicken and refrigerate for an hour or up to overnight.

Roast the tomatoes. Preheat the oven to 400°F. Line a rimmed sheet pan with aluminum foil. Add the tomatoes, ¼ cup (4 tablespoons) of olive oil, and ½ teaspoon of salt to the pan. Toss the tomatoes to evenly coat them in the oil and salt. Roast for 15-20 minutes.

Cook the chicken. Heat a skillet over medium heat and drizzle with olive oil. Add the chicken and cook, turning every few minutes, until the chicken is browned and reaches an internal temperature of 160°F, about 10-15 minutes.

While the chicken cooks, bring a large pot of generously salted water to a boil. Cook the pasta according to package instructions until al dente. Drain and add the hot pasta to the skillet with the chicken. Toss with the pesto, roasted tomatoes, and spinach. Top with freshly grated Parmesan and fresh basil before serving.