Dry the scallops. Arrange cleaned sea scallops on a plate lined with paper towels, then place another paper towel on top and gently press down. Let them sit for 10–15 minutes to remove any excess moisture. Once dry, season both sides with 1 tsp of Kosher salt and ¼ tsp of black pepper.
Cook the orzo pasta. Bring a large pot of water to a rolling boil. Generously season with Kosher salt (about 3–4 Tbsp). Add the orzo and cook for about 7 minutes, or until al dente according to package instructions. Reserve 1 cup of the pasta water, then drain the orzo and set it aside. Return the empty pot to the stove.
Dredge the capers. Place ¼ cup of drained capers into a small bowl. Add 2 Tbsp of cornstarch and toss until the capers are evenly coated.
Fry the capers. Warm 3 Tbsp of neutral oil in a small skillet over medium-high heat. Once hot, carefully add the dredged capers using a slotted spoon or spider, shaking off excess cornstarch. Fry for about 3 minutes, or until they turn crisp. Transfer them to a paper towel–lined plate to drain and set aside.
Sauté the corn. In the large pot (used for the orzo), heat 1 Tbsp of olive oil and 1 Tbsp of butter over medium-high heat. Once melted, add the corn and cook for 3–4 minutes, stirring occasionally. Season with the remaining ½ tsp of Kosher salt, then stir in ½ cup chopped sun-dried tomatoes and cook for 1 more minute.
Finish the pasta. Add the drained orzo back to the pot with the corn. Stir in ¼ cup of pesto, the zest and juice of 1 lemon, ½ cup of mascarpone cheese, and ¼ cup of grated Parmesan. Pour in ½ cup of the reserved pasta water and stir until well combined. Taste and adjust the seasoning. If you prefer a looser sauce, add more of the reserved pasta water. Transfer the pasta to a large serving bowl.
Cook the scallops. Heat a large cast iron or stainless steel skillet over high heat. Once very hot, pour in the remaining 3 Tbsp of neutral oil. Carefully arrange the scallops in the skillet, leaving about an inch between each. Cook for 2–3 minutes, or until they form a deep golden crust. Add 2 Tbsp of unsalted butter, then quickly flip each scallop. Cook for 1 more minute, basting them with the browned butter.
Finish, then serve. Place the seared scallops on top of the pasta, then drizzle any leftover browned butter from the skillet over them. Sprinkle the fried capers on top, along with a pinch of flaky sea salt and extra black pepper if desired. Serve immediately.