Vegetarian Brown Rice Salad With Parsnips and Whipped Ricotta

Arrange a rack in center of oven; preheat to 450°F. Mix rice, 1 Tbsp. oil, a pinch of salt, and 5 cups water in a medium heavy saucepan. Cover and bring to a boil, then reduce to a simmer and cook until rice is al dente, about 25 minutes. Drain, then rinse with cool water; set aside.
Meanwhile, zest 1 orange and transfer zest to a small bowl; reserve orange. Toss parsnips, garlic, rosemary, cayenne, 1/2 cup oil, 1/2 tsp. salt, and 1/4 tsp. orange zest on a rimmed baking sheet. Roast, tossing once halfway through, until fork-tender, about 20 minutes. Transfer to a plate.
Toast hazelnuts on rimmed baking sheet, tossing occasionally, until golden brown, 6–8 minutes. Let cool, then coarsely chop.
Blend ricotta, 2 Tbsp. oil, and 1/2 tsp. salt in the bowl of a stand mixer fitted with the whisk attachment (or use a whisk) until smooth and fluffy, about 2 minutes.
Peel remaining orange. Slice into 1/4" rounds, then cut into half moons.
Juice reserved orange. Whisk vinegar, honey, pepper, 2 tsp. orange zest, 3 Tbsp. orange juice, and remaining 1/4 cup oil and 1 tsp. salt in another large bowl until smooth.
Toss rice, parsnips mixture, lettuce, orange rounds, hazelnuts, and parsley in bowl with vinegar mixture. Spread ricotta mixture on a platter and arrange salad over. Serve immediately.
Rice and parsnips can be prepared 2 days ahead; store in separate containers, cover, and chill.