In a large skillet, cook the bacon over medium heat until crisp, about 8 minutes,; drain, reserving 2 tbsp. of the fat.
Meanwhile, using a food processor, coarsely chop the peanuts. Reserve 2 tbsp., then finely chop the remaining nuts. Add the butter and 1 1/2 tsp. maple syrup; puree.
In a large bowl, whisk together the flour, baking soda and salt. Make a well in the center; whisk in the yogurt, eggs, 1/2 cup water, 2 tbsp. syrup and reserved bacon fat until smooth. Fold in the bananas and crumble in the bacon.
Heat a griddle or skillet over medium heat, lightly grease. Working in batches, drop the batter by 1/3 cupfuls. Cook until bubbling on top and golden underneath, 3 minutes; flip and cook until springy, 1 minute. Transfer to a plate and cover to keep warm. Repeat with the remaining batter.
Spread some of the peanut butter on each pancake, then assemble on plates in stacks of 3; drizzle with more syrup and sprinkle with the reserved 2 tbsp. chopped peanuts.