Preheat the oven to 400°F.
Prepare the peach filling. Thinly slice the peaches and add to a bowl. Add the remaining filling ingredients, reserving the tapioca flour. Toss until the peaches are well coated.
Now, let's cook the peaches. Warm a skillet over medium heat and melt 1 Tbsp butter. Add the peaches and cook, stirring regularly, until tender and jammy with plenty of juices, about 5–8 minutes.
Sprinkle the tapioca flour evenly over the peaches and stir until the liquid thickens and turns glossy, 1–2 minutes. If you prefer, whisk the tapioca with a teaspoon of cool water first to make a slurry, then stir it in. Remove the peaches and juices from the skillet and set aside.
Prep the skillet to bake the pancake. Place the skillet back on the stove over medium low heat, and melt 2 Tbsp butter and swirl to coat.
Blend the pancake batter. Add all pancake ingredients to a blender and blend until smooth.
Immediately pour in the batter to the skillet and transfer to the oven. Bake 13-14 minutes the pancake is until puffed, cooked through, and golden brown. Do not open the stove during the baking process! This will cause the pancake to deflate, which you do not want.
Once the pancake if finished cooking, remove from the oven, spoon the warm peach filling on top, and serve right away with maple syrup and a dusting of powdered sugar. Enjoy!