I've been meaning to bake some cupcakes in jars since I bought some heat resistant glass jars last year. Two of my nieces ( bro's daughters) celebrated their birthdays last month so I had an excuse to bake some. I used Betty Crocker Devil's Food cake mix. Since I was not baking a huge batch of cupcakes, I just baked them in a preheated toaster oven for 20 minutes. When the cupcakes cooled completely, I frosted them with buttercream and personalized each jar. They came out absolutely adorable and yummy! Maybe next time I'll try to bake some pies in jars too!