Boil the water, either on the stove top or in the microwave in a large Pyrex cup measure. Add salt and stir to dissolve the salt. It won’t all dissolve so don’t worry if there’s some left.
Add the vegetable oil to the salt mixture and stir.
Place the flour in a mixing bowl and add the salt mixture and stir, stir, stir. Use your hands eventually. If the mixture seems dry, add water in 1 tablespoon increments until a soft dough forms. Knead until it’s smooth.
Cover the dough and let it sit for an hour, this is optional, but I think it makes the texture smoother.
Knead the dough again until it's soft and pliable. Roll the dough to your desired thickness. I used about ¼ inch thickness. Select a small oven safe bowl to give your dish it’s shape.
Help your child press his or her handprint into the dough.
Make sure the impression is deep. Cut out the area around the handprint in a round shape that will fit into your bowl. Place your slab, with handprint side up, into the bowl.
Optional - use the remaining dough to make a flat hand print ornament.
Preheat oven to 180°F.Place your bowl on a baking sheet and bake for two hours. By then you should be able to remove the dish from the bowl and it’ll hold its shape.
Place the dish upside down to cure the bottom side and bake for two to three more hours depending on thickness. Don’t try to rush this by baking at a higher temperature or the dough may puff up and ruin your handprint. Bake until solid and dry.
Let cool completely. Smooth any uneven or sharp points with sandpaper or a emery board . Paint as desired. Better yet, let the kiddie paint it. Paint according to directions on your paint. I used Waverly metallic paint in White Opal and Moonstone.