Wash and dry produce.

Trim and thinly slice scallions, separating whites from greens. Thinly slice jalapeño into rounds, removing ribs and seeds for less heat.

Heat a drizzle of oil in a small pot over medium-high heat. Add scallion whites; cook, stirring, until fragrant, 30 seconds. Stir in rice, half the sesame seeds, 1½ cups water (3 cups for 4 servings), and a pinch of salt; bring to a boil. Once boiling, cover and reduce to a low simmer. Cook until tender, 15-18 minutes.

Keep covered off heat until ready to use in Step 3.

While rice cooks, in a small bowl, whisk together guacamole, half the mayonnaise, and half the Sriracha. Season with salt and pepper to taste. Reserve 1 TBSP creamy chili guac (2 TBSP for 4 servings) in a medium bowl (set remaining creamy chili guac aside for serving). 

Add sweet Thai chili sauce to bowl with reserved creamy chili guac. Whisk to combine; set aside. 

In a separate small bowl, whisk together remaining mayonnaise and remaining Sriracha. Season with salt and pepper to taste. Set aside. 

Once rice is done, crumble half the roasted seaweed sheets into pot. (Reserve remaining seaweed sheets for another use!) Using a wooden spoon, stir until rice begins to stick together, 1 minute. Add vinegar, cornstarch, and 1 tsp sugar (2 tsp for 4); stir until well combined. 

Line an 8-by-8-inch baking dish (9-by-13-inch baking dish for 4) with plastic wrap. (TIP: Leave a little plastic wrap hanging over the sides of the dish so the rice is easier to remove in Step 5.) Coat with nonstick cooking spray. 

Using the back of a spoon, press rice mixture into prepared baking dish in an even layer. (TIP: Lightly coat surface of rice with nonstick cooking spray to help prevent it from sticking to the spoon.) Transfer to freezer until completely cooled, at least 15 minutes (but no longer than 30 minutes).

Rinse shrimp* under cold water, then pat dry with paper towels. 

Heat a large drizzle of oil in a large pan over medium-high heat. Add shrimp and season with salt and pepper. Cook, stirring occasionally, until shrimp are opaque and cooked through, 4-6 minutes.

Transfer shrimp to medium bowl with sweet Thai chili guac. Stir to coat. Cover to keep warm. 

Using plastic wrap overhang, carefully lift rice mixture out of baking dish and transfer to a cutting board (discard plastic wrap). Cut into four equal squares (eight squares for 4 servings).

Heat a large drizzle of oil in a second large, preferably nonstick, pan over medium-high heat. Add rice squares; cook until browned and crispy, 3-4 minutes per side (you may need to cook in batches).

Transfer crispy rice squares to a paper-towel-lined plate. 

Divide crispy rice squares between plates. Spread each with remaining creamy chili guac, then top evenly with jalapeño and sweet heat shrimp. TIP: If desired, use less jalapeño to tame the heat. 

Garnish with scallion greens and remaining sesame seeds. Serve with spicy mayo on the side for dipping.