Set oven rack to lowest position, place sheet pan on rack and heat oven to 425ºF (218ºC).
Meanwhile, peel 2 pounds carrots then cut, on the bias, into ½-inch-thick pieces.
In a large bowl, toss carrots with 1 tablespoon olive oil and 1 teaspoon salt.
Carefully remove preheated sheet pan from oven and dump carrots on pan. Shake pan to arrange in an even layer then return to oven and roast 20 minutes. Using a spatula, scrape up carrots and flip; continue roasting until tender and starting to brown, 10–15 more minutes.
Set a fine mesh sieve in now-empty bowl used to toss carrots and oil; set aside.
Heat remaining 3 tablespoons oil in a skillet over medium until shimmering. Add 2 sliced shallots, separating sliced rings as you add them to the oil, and cook, shaking skillet occasionally, until shallots are starting to brown, about 3½ minutes. Add 2 tablespoons pepitas and continue to cook until shallots are golden brown and pepitas are toasted, about 1½ minutes. Add ¼ teaspoon pepper flakes and cook 15 seconds. Remove from heat and immediately pour mixture through fine mesh sieve set in bowl.
Transfer fried shallot mixture to a paper-towel-lined plate and sprinkle with salt.
Add 1½ cups farmer cheese, ¾ teaspoon salt, and ½ teaspoon vinegar to infused oil and whisk to combine. Spread into an even layer on a large platter.
Sprinkle fried shallot mixture over roasted carrots then, using a spatula, arrange carrots and shallots over farmer cheese. Sprinkle raisins over top and serve.