By Kayla Hoang, The New York TimesAs a recipe creator, digging into a recipe, ingredient by ingredient, is my favorite part of the job. Often, it’s easy to predict how they’ll act and adjust accordingly. Sometimes, though, a recipe can feel impossible to crack. Enter butter rice cakes. Also known as Shanghai butter mochi and butter tteok, butter rice cakes are a style of mochi that are subtly sweet and deeply buttery. They have taken the internet by storm, especially in South Korea. As with many viral recipes, this one’s history is vague. The cakes are often attributed to bakeries…