Preheat your oven to 350°F. Grab a 9-inch round cake pan and melt 2 tablespoons of butter in the bottom. Sprinkle the ½ cup brown sugar and 1 teaspoon cinnamon evenly over that melted butter, creating your caramel base.

Arrange your 3 sliced peaches in a single layer on top of the brown sugar mixture. They'll overlap slightly, which is perfect—don't worry about making it Instagram-perfect. This gets more beautiful once it caramelizes anyway.

In a large bowl, cream together the ½ cup softened butter and 1 cup granulated sugar until it's light and fluffy. This takes about 2 minutes with an electric mixer. I usually see it turn pale yellow and get kinda fluffy-looking, which signals it's ready.

Add your 2 eggs one at a time, beating well after each addition. Then stir in the 1 teaspoon vanilla bean paste. The mixture should look smooth and creamy, not separated or grainy (don't panic if it looks a little lumpy at first—keep stirring).

In a separate small bowl, whisk together the 1½ cups flour, 2 teaspoons baking powder, and ¼ teaspoon salt. Now alternate adding the dry mixture and ½ cup milk to your wet ingredients, starting and ending with dry. Mix until just combined—don't overmix or your peach upside down cake cozy will get dense.

Gently pour your batter over those peaches in the pan, spreading it evenly. Don't press down or move things around—let the batter settle naturally. Bake for 40-45 minutes until the top is golden brown and a toothpick inserted in the cake (not the fruit) comes out clean.

Let it cool in the pan for about 5 minutes. Then run a thin knife around the edges and place your serving plate on top of the pan. Flip it quickly and confidently—this is the fun part. If any peaches stick, just pop them back on top with a small spatula.