Preheat the oven to 325ºF. (162°C)
Measure the oats, flour, and baking powder into a mixing bowl and whisk till combined.
Add the bacon and stir till combined. Mix the peanut butter and water in a glass measuring cup. Make a well in the flour, and add the peanut butter and water mixture all at once. Mix on medium speed using a paddle attachment until combined. The mixture should form a soft dough.
Turn the dough out onto a lightly floured surface and gently knead till the dough is smooth and soft. Roll the dough ¼-inch thick, and cut out the biscuits using a cookie cutter.
Place the biscuits on a parchment-lined cookie sheet and bake for 12– 15 minutes till they are dry and firm to the touch. Turn off the oven and leave the biscuits in another 20– 30 minutes.
Remove them from the oven, cool them on a baking rack, and store them in a cookie tin.