I used some great Anna Maria Horner Fabric "Good Folks Button" along with a thin cotton batting, extra wide double fold bias tape, and unbleached cotton for the inside. I really think that the Anna Maria Horner fabric was perfect for this project.
*Please make sure to use 100% cotton fabrics and materials for this project. Synthetics and the microwave don't mix.
Now I didn't have a pattern but I used my old tortillero as a guide. It is a simple project and the most difficult part of the project is attaching the bias tape. I simply traced a plate for my circle, my circle ended up being about 10 inches in diameter, but you could make it larger if you wanted it to accommodate larger flour tortillas. I cut out two circles of the bat, unbleached cotton, and my print.
I then sandwiched the pieces together with the print on top, bat in the middle, and unbleached cotton on the bottom. I made two separate fabric stacks.
I stitched around the perimeter of the circles securing the layers.
Next I quilted each stack of fabric. I ended up following the print on my fabric because it had very definite lines, but they ended up being about two inches apart.
After quilting each piece I marked my circles in quarters using pins. You will be basically making an envelope out of your circles, so one half of the circles will be connected and the other end will be left open.

Next I pinned my two stacks of fabric together at three of the four quarter points. I began sewing my bias tape to the open end of the top circle. I like to fold the bias tape in at the end to avoid any raw edges. I stitched near the edge of the bias tape around the first half of the top circle.
When I came to the midpoint I made a small clip on the underside of the bias tape to allow for the added bulk of the two layers. Sew bias tape around the second half of the circle including both stacks of fabric in the tape.
When you reach the beginning of the bias tape you will need to begin sewing only around the bottom circle. I made a small clip on the top side of the bias tape and a small clip (just to the stitch line) in the top layer of fabric allowing the bias tape to bypass the top layer.
I then attached the bias tape to the remaining portion bottom circle. When you reach the end leave enough tape to cover any exposed fabric on the bottom seam of your tortillero. Secure the ends of your bias tape by stitching toward the inner edge of the bias tape, or use a satin stitch to secure the ends.
I am excited to make another of these. I think that I will be able to work out the little kinks that made them manifest in the sewing process. This was a relatively simple and quick project. Hopefully it will keep your tortillas and your belly nice and warm.
I used our tortilla cozy just the other day when I was making enchiladas. I needed the tortillas to be warm and pliable, but I wasn't going to warm them on a comal, I simply placed a stack of tortillas in the cozy and threw them in the microwave for 1 minute. They were nice and warm and perfect for rolling.
Let me know if you try this project out.