Plum Easy Patterns
Rounded Folded Star Hot Pad pattern - PEP-101
Includes: pattern and one interfacing template. You will need one template per hot pad as the triangles are not pieced together, but laid over-lapping each other and the interfacing forms a basis for the hot pad, as well as being a ruler to position the triangles on.
The star is built with 4 layers of folded triangles plus batting, making it thick enough to protect a surface from a hot plate.