Preheat the oven to 350°F (180°C) or 160°C fan. Grease a 9-inch round cake pan with the 4 tablespoons melted unsalted butter, coating the base and sides.
Drain the 18-ounce can of sliced pineapple in a colander. Pat the pineapple slices and the 8 maraschino cherries (or strawberries) dry with paper towels.
Evenly sprinkle the 1/2 cup packed light brown sugar over the bottom of the greased pan.
Arrange the pineapple slices on top of the brown sugar: place one slice in the center, then arrange the remaining slices around it (use full or half slices as needed). Place the 8 cherries (or strawberries) inside the rings or between slices. Gently press the fruit into the brown sugar to adhere, then set the pan aside.
In a medium bowl, whisk together the 1 3/4 cups sifted all-purpose flour, 1/4 teaspoon salt, 2 teaspoons baking powder, and 1/2 teaspoon ground cinnamon.
In a large mixing bowl, beat the 1/2 cup unsalted butter (room temperature) with the 3/4 cup granulated sugar until light and fluffy. Beat in the 2 large room-temperature eggs, one at a time, then beat in the 1 teaspoon vanilla extract, scraping down the bowl as needed.
Add the dry ingredients to the butter mixture alternating with the 1/4 cup milk (room temperature): begin with a portion of the dry ingredients, add some milk, and continue alternating, mixing only until just combined. Do not overmix.
Spoon the batter evenly over the arranged pineapple and cherries, gently spreading to cover the fruit.
Bake for 55–65 minutes, or until a toothpick inserted into the center of the cake comes out clean and the top is golden.
Remove the cake from the oven and let it rest in the pan for about 5 minutes. Run a knife around the edge if needed, place a serving plate over the pan, invert the cake onto the plate, lift off the pan, and let the cake cool until warm or room temperature before slicing and serving.