This is really easy to make and so delicious. I use my Grandma Mel's recipe for the topping.
12 ripe plums (I used Black Friar, but any plums or pluots will do)
1/4 cup Royal Rose Cardamom-Clove Syrup
1/4 cup sugar (turbinado or granulated)
1 tablespoon fresh lemon juice
1 teaspoon cinnamon
Prepare the plums: Slice in half, remove pits, and cut each half into 3 or 4 slices. Put the sliced plums into a baking dish (a pie dish or glass or ceramic casserole works fine); drizzle syrup and sprinkle the sugar, lemon juice, and cinnamon over the plums.
6 tablespoons soft butter
1/2 cup brown sugar
1/2 cup quick cooking oats
6 tablespoons flour
Mix the butter and sugar together, then add the flour and oats until it forms a soft paste. Put on top of plums so that it covers all or most of the fruit. Place the plum crumble into an oven preheated to 350 degrees and bake for 30 minutes or until the crust is golden brown and the plums are bubbling.