Place the bananas in a large bowl and mash until smooth. Add the yogurt, lard, and baking soda and mix well.

Stir in the oats. Add the flour, a half cup at a time, until the dough is too stiff to stir. Then knead in the remaining flour.

Next, roll the dough out about a centimeter thick on a flat surface, lightly coated in flour. Use a cookie cutter to cut out treats the shape and size you desire.

Spritz a cookie sheet with oil and lay your treats out on it. Bake at 350°F until the edges turn golden brown, about 12-20 minutes.