Here’s proof that strudel can be prepared from scratch, even for beginner bakers. The dough is mixed together by hand and is refreshingly forgiving when rolling out. The rich filling, with a subtle tang from the addition of sour cream, is also the epitome of etherealness, thanks to all the beaten egg whites that are folded into it. You’ll want to share something this delicious with family and friends, either as a holiday dessert or a packaged gift.