THE FIX: It’s not that uncommon to double a recipe for a dinner party or halve it when you’re only serving two. It’s basically just a matter of math and measurements, right? Yes and no. It’s no big deal in many dishes, but it’s not universally true, particularly in baking. Doubling or halving a recipe changes the calculated chemistry of the ingredients and affects the rate at which they cook. For example, doubling a quick bread recipe and then creating a larger, wider loaf increases the surface area that’s exposed to the heat, changing the rate at which it cooks. The best advice when it comes to scaling recipes in baking is not to do it. If you must increase the quantity, make the same recipe in multiple batches.