For the dog cookies with bacon, preheat the oven to 180 degrees. Let the boiled and peeled potatoes cool down, mash them or press them through a potato press.
Add the flour, oatmeal and finely diced bacon to the potatoes and mix with a mixer to form a dough.
Roll the dough out thick (about 1 cm) and cut even squares with a knife or pizza wheel and spread on a baking sheet.
Bake the dog cookies with bacon for 25 to 30 minutes.