Preheat the oven to 350°F (175°C). Halve the cherry tomatoes and place them cut-side up in a large ovenproof baking dish.
Mix a big splash of olive oil with about 1 teaspoon brown sugar and a few pinches of salt, pour over the tomatoes, toss gently to coat, then roast for about 45 minutes until they are shrunken and sweet.
Bring a large pot of salted water to a boil and cook the penne according to package instructions until al dente; reserve 1 cup of the hot pasta water before draining.
Make the sun-dried tomato pesto: in a food processor pulse the sundried tomatoes, garlic, red pepper flakes, olive oil, fresh thyme, and salt until a textured paste forms.
Add the toasted pine nuts to the food processor and pulse a few times to incorporate while keeping some texture; set the pesto aside.
In a large mixing bowl combine 1/2 cup of the reserved pasta water with two-thirds of the sun-dried tomato pesto.
Add the drained penne to the bowl and toss gently; add more reserved pasta water as needed to achieve a chunky sauce, and add more pesto to taste.
Arrange the dressed baby spinach on a large platter, pile the tossed pasta on top, then scatter the roasted cherry tomatoes over the pasta and finish with crumbled goat cheese and toasted pine nuts.
