Preheat the oven to 350F degrees.
Combine crushed pretzels, brown sugar, and melted butter in a medium-size bowl. Press the mixture onto the bottom of an 8x8 pan or baking dish. Bake, uncovered, for 10 minutes. Let cool to room temperature (about 20 minutes).
Meanwhile, combine boiling water (see Notes for microwave time) and strawberry gelatin, stirring until gelatin is dissolved. Stir in 1/2 cup cold water. Place in refrigerator until slightly thickened to the consistency of egg whites (about 20 minutes-which is perfect for the timing of the crust to cool down). (Be careful not to let it get too thick at this point.)
To avoid using an electric mixer, I get the cream cheese very soft by microwaving it. Unwrap the cream cheese and place on a plate. Microwave on HIGH for 10 seconds; flip it over and microwave again for 10 seconds. The cream cheese should be soft enough to stir with a whisk or spoon.
Whisk together softened cream cheese and granulated sugar. Whisk until sugar is almost dissolved. Gently fold in Cool Whip with a spatula until you don’t see any streaks of cream cheese.
When the crust is about room temperature, dollop the cream cheese filling onto the crust, then spread evenly to the edges of the pan. This step is important so the gelatin won’t seep down to the crust.
Add the sliced strawberries to the gelatin or arrange on top of cream cheese mixture. It should slightly thickened at this point but still pourable. Pour or spoon the strawberry mixture over the filling and spread it all the way to the edges of the pan.
Place in the refrigerator, uncovered, for at least 2 hours or until the gelatin is firm. Cover and store in the refrigerator until ready to serve.
Cut into squares to serve. Dollop with additional Cool Whip, if desired.