Preheat your oven to 350°F (175°C). Lightly grease a 9x13 inch baking dish to prevent sticking.
In a large mixing bowl, beat together the cake mix, eggs, 1 ½ cups of heavy cream, and vegetable oil with a mixer until the batter is smooth and well combined. Pour this delicious batter evenly into your prepared baking dish.
Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out with just a few moist crumbs. Be careful not to overbake! Remove the cake from the oven and let it cool in the pan for 20 to 30 minutes.
Once slightly cooled, use the round handle of a wooden spoon to gently poke holes all over the top of the cake. Aim to go about two-thirds of the way down – make sure not to poke all the way through the bottom.
In a medium, heat-safe bowl, whisk the strawberry gelatin powder with 1 cup of boiling water until the gelatin is completely dissolved (this usually takes about 2 to 3 minutes).
Slowly whisk in the remaining 1 cup of heavy cream into the dissolved gelatin mixture until it's fully combined and creamy.
Carefully and slowly pour the strawberry-cream mixture evenly over the poked cake, making sure to fill those little holes as much as possible. Cover the cake and chill it in the refrigerator for at least 4 hours, or even better, overnight. This chilling step is essential for the jello to set and for the flavors to meld beautifully!
Once the cake is thoroughly chilled and the jello has set, uncover it and spread the thawed whipped topping evenly over the surface.
In a food processor, pulse the vanilla sandwich cookies several times until they are broken into small crumbles. Drizzle in the strawberry syrup over the crumbs and pulse again several times until the syrup is combined and you have a lovely pink and white crumb mixture. (If you don't have a food processor, you can place cookies in a ziploc bag, crush them with a rolling pin, add syrup, and shake to combine).
Evenly sprinkle the homemade strawberry crunch topping over the whipped topping. Garnish with fresh sliced strawberries if you like for an extra touch of freshness, then slice and enjoy your refreshing poke cake!