Preheat oven to 350°. Mix together dry ingredients.
Mix in the peanut butter and hot water. You may need to add more flour if the dough is too sticky.
Knead dough well.
Roll the dough into 1/4" thickness and cut into shapes with dog cookie cutters.
OPTIONAL: Egg wash (one egg whisked with a fork and then brushed on with a pastry brush) on the treats before I baked them. It gives them a nice sheen once they're baked. Here's how they look before baking.
Bake on a lightly greased cookie sheet for 40 minutes. Turn off the oven and let them cool overnight.
If you and your dog can't wait that long, cool them completely on a wire rack before serving.
Instead of cutting out more shapes with the left over peanut butter and oatmeal dough, I rolled it into balls. Then I made a cross hatch fork mark on the dog cookies. This is the same way you would do for human peanut butter cookies.
After: The cookies get very hard, just the way dogs like them!
Storing: This peanut butter dog biscuit recipe makes biscuits that will last in a sealed air tight container at room temperature for one week. You can store them in the refrigerator for 3 weeks and in the freezer for up to 6 months.