I like stuffed jalapenos, too. My husband got me one of these racks that you can use on the grill or in the oven; really helps to keep them upright and cooking evenly:
https://www.amazon.com/King-Kooker-36JR-Stainless-Steel-Jalapeno/dp/B001LF3SV6/ref=sr_1_1?keywords=king+kooker+jalapeno+rack&qid=1559398128&s=gateway&sr=8-1
What will they think of next?