In a small bowl, drizzle the maple syrup evenly inside a 8x8 square or round glass** baking dish and spread evenly across the bottom of the pan.
Lay the sliced peaches evenly over the syrup. Chop up any remaining peaches, if desired, and set aside.
Back in the bowl, combine the milk, molasses, vanilla, and flaxseed. Set aside.
In another bowl, stir together the remaining (dry) ingredients.
Pour the wet ingredients, along with the diced peaches into the dry ingredients, and stir just enough to combine.
Spoon or pour the batter over the arranged peach slices.
Bake for 35-45 minutes***, until toothpick or cake tester comes out clean. Allow to cool about 10 minutes, then slide a butter knife around the edges of the pan to loosen the cake and ease removal. Invert the cake by placing a large plate or serving tray over the cake and turn it over. Place it on the counter and tap the bottom of the cake pan gently until it releases.
Store covered in the refrigerator for up to 5 days.
Notes
* I typically use 2 peaches – 1 ½ to line the bottom of the pan and about ½ diced in the batter. But if you slice your peaches thicker or use a larger pan, you may need a third peach.** I use a glass 8x8 square pan or glass round pan. No greasing or oil required – it comes out easily every time. I haven’t baked this cake in a metal pan – but you may need to line a metal pan with parchment paper.*** When I bake this cake in an 8x8 glass square pan, it takes closer to 35 minutes. When I use a round glass pan, it takes about 45 minutes. Be sure to use a cake tester or toothpick to ensure it’s completely cooked through.This Peach Upside-Down Gingerbread Cake is delicious warm or at room temperature. Feel free to add chopped pecans or walnuts. It's also delicious with apples. Just core and slice apples instead of peaches. Yum!