Columnist Dorie Greenspan answered reader questions in a recent online chat.

Q. I've made my own granola and am looking forward to trying yours, especially with the cocoa added. But whenever I add dried fruit, the pieces become rock-hard after a couple weeks, even in an airtight container. How can I correct this?

A. It's just in granola's nature that the dried fruit dries hard over time, but there are a couple of things you can do to prolong the quality of your granola.

First, if you're going to add dried fruit, make sure it's plump and moist. I always soak the fruit in very hot water for at least five minutes, drain and pat it dry before I add it to the granola.

And don't bake the fruit with the granola - add it after the granola is baked.

You can also wait to add the fruit and just toss it in each time you're using the granola.

Q. I've been on a granola binge for at least a year. I use Molly Wizenberg's recipe, and as soon as we run out, I make some more. The only tweak I've made is to add some maple syrup to the honey/oil mixture. (I used this granola in your granola cake, and it was a big hit.) I'm interested to try adding some cocoa powder and vanilla, per your recipe for Cocoa Crunch Fruit and Nut Granola.

A. I think you'll like the bit of cocoa in my recipe - you can add even more if you'd like - and I'm sure you'll like the vanilla. I'd made granola for years without vanilla, and once I added it, it was an aha experience.

Q. I made the Dorie Greenspan's Custardy Apple Squares a few weeks ago, and for this novice baker, they were quite the success. You mentioned that other fruit, such as mangoes, may be substituted. Are there any recipe changes when using mango? How would you cut them?

A. If you want to use a mango, slice it from top to bottom. Precision doesn't count for much here.

Q. My new oven runs oddly. Lots of cookies seem to take longer than the recipe states, and the texture is sacrificed when I'm waiting for the cookies to brown. Would using the convection feature help? Or baking one sheet at a time instead of two?

A. Convection might help to even out the heat circulation. I'd suggest you make a few test sheets of cookies with just one or two cookies on the baking sheet so that you can figure out how you need to adjust the temperature for convection. The rule of thumb is to set a convection oven 25 degrees lower than a conventional oven, but each oven is different.