Preheat oven to 350 degrees Fahrenheit. Cook egg noodles in a large pot of boiling salted water, stirring occasionally, until al dente, about four to five minutes. Drain, leaving a little bit of water clinging to the noodles.

Generously butter a 9×13-inch glass baking dish.

Make the creamy sauce: Cut one stick butter into a few big pieces and transfer to a small heatproof bowl. Microwave until butter is melted, about one minute. Let cool slightly. Whisk the eggs and sugar in a large bowl until sugar is dissolved and eggs are frothy, one to two minutes. Add cottage cheese, sour cream, vanilla extract, ground cinnamon, nutmeg, and kosher salt to egg mixture. Whisk vigorously to combine. Pour in melted butter and whisk again to combine.

Add hot noodles and raisins to bowl and toss to coat with a spoon or spatula.

Transfer noodle mixture to prepared baking dish, tipping dish to evenly distribute.

Stir together crushed cornflakes, ground cinnamon, and remaining two tablespoons sugar in a small bowl, then sprinkle mixture evenly over noodles. Dot with remaining two tablespoons unsalted butter, cut into pieces.

Bake kugel, rotating pan halfway through, until custard has souffléed, top is browned, 50–60 minutes.