This recipe was posted quite some time ago by Dawn Maynard and I think it might be what you are looking for...
Recipe(tried): Fresh Strawberry Cake (using cake mix)
From: Dawn Manard, Omaha 5-17-2002 Daily Recipe Swap
In reply to: Recipe: Dessert Recipes (23)

Fresh Strawberry Cake

1 box of duncan hines strawberry cake mix
1 pound fresh strawberries, rinsed and hulled
1 (8 oz) carton cool whip, thawed
1 large box instant vanilla pudding mix

Make cake according to directions on box. Pour into 9 x 13 pan. Bake 30-35 minutes in a 350 deg oven. Cake should be cooked until tester comes out clean. Cool 30 minutes.

Puree strawberries in blender or food processor. Poke holes with fork or large spoon handle in cake. Pour strawberries over. Allow 10 minutes to soak in.

Meanwhile, mix pudding mix according to directions for pudding pie. Allow to cool in fridge for 5 minutes. Mix cool whip in with pudding. "Frost" cake with pudding/cool whip mixture.

Friends and family always love it when I make this. It's light and fresh. Good spring thing.