Creating the Cranberry Pineapple Upside Down Cake is straightforward. Follow these steps for a delicious result:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan.
2. Prepare the Topping: In a medium saucepan, melt the butter over medium heat. Stir in the brown sugar until fully combined and bubbly. Pour this mixture into the prepared pan.
3. Arrange the Pineapples: Place the drained pineapple slices on top of the brown sugar mixture. Scatter the cranberries evenly over the pineapples.
4. Mix Dry Ingredients: In a large bowl, whisk together the flour, baking powder, and salt.
5. Combine Wet Ingredients: In another bowl, beat the eggs, granulated sugar, milk, and vanilla extract until well blended.
6. Combine Mixtures: Gradually add the dry ingredients to the wet ingredients, mixing until smooth and well incorporated.
7. Pour Batter: Carefully pour the batter over the arranged fruits in the pan.
8. Bake: Place the pan in the preheated oven and bake for 40-45 minutes, or until a toothpick inserted in the center comes out clean.
9. Cool: Remove the cake from the oven and let it cool in the pan for about 15-20 minutes.
10. Invert the Cake: Carefully run a knife around the edges to loosen the cake, then invert it onto a serving platter. Allow it to cool slightly before serving.

These steps will guide you in creating this amazing cake with ease. Enjoy the delightful aroma as it bakes, and prepare for a delicious treat!