Preheat the Oven: Preheat your oven to 350°F (175°C).
Prepare the Cake Batter: In a large mixing bowl, combine the undrained pineapple, all-purpose flour, sugar, eggs, and baking soda. Beat until smooth.
Bake the Cake: Pour the batter into a greased 9x13-inch baking dish. Bake for 30-35 minutes, or until a toothpick comes out clean.
Cool the Cake: Let the cake cool for 15 minutes.
Prepare the Icing: In a separate bowl, beat the softened cream cheese, butter, powdered sugar, vanilla extract, and milk until smooth.
Frost the Cake: Spread the icing over the warm cake and let it cool completely before serving.