– ¾ cup brown sugar – ½ cup granulated sugar – ½ cup butter softened – 1 egg – 1 teaspoon vanilla – 1 cup buttermilk  – 2 cups flour – 1 teaspoon baking soda – ½ teaspoon salt – 2 cups chopped rhubarb

For the topping: – ½ cup sugar – 3 tablespoons butter – ¼ teaspoon cinnamon – ½ cup shredded coconut – ½ cup chopped pecans – To serve: whipped cream

Place the brown sugar, granulated sugar, and butter in a large bowl. Mix on high with a hand mixer until light and fluffy.

Add the egg and vanilla, and mix to combine. In another large bowl, whisk together the flour, baking soda, and salt.

Add half the flour mixture, followed by half the milk, and mix to combine. Repeat with the remaining flour mixture and milk. Stir in the rhubarb.

For the topping, rub the butter into the sugar using your fingers until small lumps form.  Stir in the pecans, coconut, and cinnamon. 

Pour the cake batter into a greased 13x9 inch pan, and top with the coconut crumble. Bake at 350°F for 45–50 minutes, or until a toothpick inserted into the center comes out clean.

Cut into slices, and serve topped with whipped cream or whipped topping.  I like serving it while it's still a little warm from the oven.