Preheat oven to 350°F. Spray or grease & flour a 13"x9" baking dish.
In a large mixing bowl, whisk together flour, brown & white sugar, cinnamon, baking powder, baking soda, nutmeg and cloves.
Cut in butter (with a pastry blender) until mixture is pea sized crumbled.
Set aside 1 cup crumb mixture.
Add 1/4 cup reserved pineapple syrup, eggs, buttermilk and vanilla extract to mixing bowl. Mix until combined.
Stir in crushed pineapple until combined. Any optional ingredients can be stirred in here or sprinkled on top.
Pour cake mixture into prepped 13"x9" baking dish. Sprinkle with 1 cup reserved crumb mixture.
Bake until toothpick inserted in center of cake comes out clean, about 45-50 minutes.
Cool on wire rack. Cake can be served warm or cold.
Cover and enjoy cake within a day or two. Store covered in fridge after second day