Step 1: Prepare the Peach Mixture:
In a bowl, gently toss the sliced peaches with granulated sugar (if using) and cinnamon (if using). This enhances their natural sweetness and adds a warm, aromatic touch. Allow the peaches to sit for about 10 minutes to release some of their juices, creating a more flavorful filling.
Step 2: Prepare the Cake Batter:
In a separate large bowl, combine the yellow cake mix, melted butter, eggs, milk, and vanilla extract. Mix until just combined, being careful not to overmix. Overmixing can result in a tough cake. The batter should be smooth and slightly thick.
Step 3: Assemble the Cake:
Pour half of the cake batter into a greased and floured 9x13 inch baking dish. Spread the batter evenly. Arrange the peach slices evenly over the batter. Pour the remaining cake batter over the peaches, spreading it gently to cover as much of the peach layer as possible.
Step 4: Bake the Cake:
Preheat the oven to 350F (175C). Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean. The top of the cake should be golden brown and the edges slightly pulling away from the sides of the pan.
Step 5: Cool and Serve:
Allow the cake to cool in the baking dish for at least 15 minutes before slicing and serving. The cake can be served warm or at room temperature. It pairs perfectly with a scoop of vanilla ice cream or a dollop of whipped cream.
Optional Tips: For a richer flavor, substitute melted butter with coconut oil. To add a crunchy topping, combine 1/2 cup flour, 1/4 cup sugar, and 1/4 cup cold butter, cut into small pieces, and crumble over the cake before baking.