Organization: always read the recipe first and make sure you have ingredients at the right temperatures, as well as the equipment and space needed. This will make the process so much easier!

Baking time: all ovens and pans are different, even if they look similar. The baking time in my recipes is as accurate as can be, but it might take you more or less time. Use a thermometer inside the oven (like the OXO oven thermometer) to check that the temperature is right. I recommend you keep track of how your oven works and what tiny details you might need to adjust. 

Don't overbake: the crust is pre-baked for a few minutes to stay crunchy, and the assembled bars only need to be lightly colored. This is important so that the carmelitas are chewy and not tough.

Double batch: if you want to make twice the recipe (and who can blame you), I recommend making two pans. You can double the oatmeal crumble in one bowl but bake them separately. The baking time will be less, and you'll avoid overbaking them.

Make ahead: carmelitas keep well at room temperature for 2 days and in the fridge for several days (well wrapped). They can be frozen for a month (I wrap them in plastic wrap and then aluminum foil).

Caramel filling: if using soft caramels, scatter them, unwrapped, over the nuts. They will melt as they bake. Alternatively, melt caramel squares in a small saucepan with a few tablespoons of heavy cream and make a toffee sauce. Drizzle over before sprinkling the crumble topping.

Variations: use milk chocolate chips with semisweet chocolate chips, using the same total amount. The bars will be sweeter. Add a little ground cinnamon and vanilla extract to the oatmeal mixture for a mellower cookie bar.