Preheat the oven to 400°F. This will give you time to prep the crust while the oven gets hot.

If your pretzels haven’t already been crushed, add them to a large zip-top bag, seal it tightly, and use a rolling pin (or a meat mallet) to crush them. Aim for pieces no bigger than ¼ inch - small enough to pack together, but not so fine they turn to dust. A little texture is good here!

In a mixing bowl, combine the crushed pretzels, melted butter, and 3 tablespoons of the granulated sugar. Stir well until everything is coated and the mixture resembles wet sand. Pour into an ungreased 9x13-inch baking dish, then use the back of a spoon or measuring cup to press the mixture evenly into the bottom, forming a solid crust.

Place the dish in the oven and bake for 8 to 10 minutes. Keep an eye on it, you're looking for a lightly toasted color and a bit of crispness. Once baked, remove from the oven and set the dish on a wire rack to cool completely.

In a large mixing bowl, beat together the softened cream cheese and the remaining 1 cup of sugar until smooth and creamy. An electric mixer works great here, or you can use a stand mixer if you prefer. Once fully blended and lump-free, gently fold in the thawed whipped topping until it’s all combined and fluffy.

Spread the cream cheese mixture over the cooled pretzel crust, using a spatula to smooth it all the way to the edges of the dish. You want to seal the edges well so the next layer doesn't seep through. Pop the dish in the fridge to chill while you prep the gelatin.

In a large heatproof bowl, add the strawberry gelatin powder. Carefully pour in 2 cups of boiling water and whisk for 2 to 3 minutes, or until the powder is fully dissolved and there are no grainy bits left.

Stir the frozen strawberries into the hot gelatin. Let this mixture chill in the refrigerator for 10 to 15 minutes - just long enough to cool down and start to thicken slightly. Don’t let it set fully; you want it pourable but not watery.

Gently pour the slightly thickened gelatin and strawberry mixture over the cream cheese layer, spreading it out evenly. Sprinkle the fresh blueberries over the top - press a few in slightly if you want them to sit into the gelatin a bit more.

Place the finished dish back in the refrigerator and let it chill for at least 2 to 3 hours, or until the top layer is fully set.

Once it’s firm, slice and serve cold.