Spray a medium nonstick pan really well with cooking spray or grease it generously with butter.
Add the honey or brown sugar directly into the pan.
Place the thick slices of banana all around the pan in an even layer. Sprinkle the cinnamon all over.
Cook the bananas over medium-high heat for about 1–2 minutes until glossy and lightly caramelized.While the bananas cook, prepare the batter.
In a bowl, mash the bananas and whisk in the egg, sugar or sweetener, melted butter or oil, and milk.Stir in the flour, baking powder, and salt until combined.
Fold in any optional add-ins if using.Gently pour the batter over the caramelized bananas and lightly smooth the top.
Keep the heat on medium-high for another 1–2 minutes, then reduce the heat to LOW and cover with a lid.Cook covered for about 30 minutes. Try not to lift the lid too often while cooking.
Remove the lid and continue cooking for another 5 minutes to help the top dry slightly and allow excess moisture to evaporate.
The cake is done when the center no longer looks raw, the top springs back slightly, and the edges are bubbling and caramelized.Remove from the heat and let the cake rest until it's cooled.
Place parchment paper over the top of the cake and gently press your hands over it. Carefully place a large plate or tray on top and flip the cake in one quick motion. The parchment paper helps keep everything intact while flipping.
Serve warm and gooey on its own or with Greek yogurt, ice cream, tahini, peanut butter, or melted dark chocolate.