Photo by Vicky Wasik.
"Umami" may not be a flavour you associate with desserts, but a bit of salty-sweet complexity can take a batch of cookies from "pretty freaking good" to "downright addicting." To get extra oomph in any dessert, baked or otherwise, all you need is a bit of malted milk powder.
High priestess of desserts Stella Parks is a big fan, and I trust Parks with all things sweet. (She's basically the Stevie Nicks of baking, churning out hit after hit while remaining flawless.) At its core, malted milk powder is "a simple combination of wheat flour and malted barley extracts, along with milk, salt, and sodium bicarbonate to adjust its pH." There are a lot of different brands, and each have their own special formula, but each one can add roasty, toasty, slightly butterscotch-y and, somewhat savoury flavours to cookies, cakes, breads, puddings, or even ice cream bases. Just scoop a little in to taste, keeping in mind you may need to adjust the overall salt content, stir it into your batter, and execute the rest of the recipe as usual.
Meet the Umami Bomb of Dessert: Malted Milk Powder [Serious Eats]