If You Have Mason Jar Lids, You Also Have Makeshift Muffin Tins
If you're craving muffins but don't have a muffin tin, you don't have to wait two to three business days until your Amazon order gets here. In fact, you don't have to spend any extra money at all — as long as you have mason jar lids. You can't bake with mason jars because the glass isn't meant to withstand high oven temperatures, but their lids are another story.
Mason jar lids are made out of tinplate and can go in the fridge, dishwasher, and even the microwave oven. But more importantly for muffin-making, the band that binds the jar to the lid is typically made of 304 stainless steel (if you're not sure about yours, the description on the product's website should let you know). They're also just a little bigger than a standard cupcake or muffin liner, which usually measures one and a quarter-inch in diameter, making them the perfect substitute if you don't own a muffin tin.
Once you've separated your mason jar bands, you can use them to make a full batch of muffins or cupcakes. First, take out a baking sheet and place your bands on it, making sure there's no overlap. Then, put a muffin liner in each ring, making sure the band holds it securely. Once you fill each one with your muffin or cupcake batter, it should stay upright and in place. From there, simply allow everything to bake in the oven like you normally would and you should be left with muffins that hold their shape.
This trick doesn't just work for muffins and cupcakes — you can make muffin tops or even English muffins in mason jar rings. In some ways, this method is preferable over having an actual tin, as you can usually fit more muffins on a baking sheet. On the flip side, if you only want to make a muffin or two for a late-night snack, that's also possible with just the bands.
The downside to this method is that your batter may flop over a little more while baking since it doesn't have the proper walls of a full muffin tin. And, keep in mind that the rubber rings in the bands will get warm, so they may lose their lid-sealing qualities afterward. But if you'd like to keep using them to make muffins, this tip should do the trick.