Baking in a tiny RV is a bit like being marooned on a desert island. We have limited space for tools and supplies. And not every recipe works under survival conditions. It has to have few ingredients, require minimal equipment, and bake without complaint in our small convection/microwave oven. On our trek West, I came to realize which recipes are my true loves—the cakes, breads and cookies I can’t live without. The revelation is like the finale of a cheesy rom-com, except there’s no race to the airport before the plane takes off. My heart and head picked a dear old favorite, fudge squares. A snack-style cake that looks and cuts like brownies, it…