Crush your 2 cups of mini pretzels into bite-sized pieces (not powder — you want actual crunch texture). Melt the 1/4 cup butter in a small saucepan over low heat, then mix it with your crushed pretzels until everything's coated. Press this mixture firmly into the bottom of a 9x13 inch baking dish and set aside.
Beat the softened 8 oz cream cheese with 1/2 cup powdered sugar and 1 tsp vanilla extract until smooth and fluffy. Fold in 1 cup of whipped topping gently — you want it light and airy, not dense. Spread this mixture evenly over the pretzel crust, making sure it reaches all the edges so the jell-o layer seals properly.
Pour 1 cup of boiling water over 1 cup of strawberry gelatin mix and stir for about 2 minutes until completely dissolved. Add 1 cup of cold water and chill for 25-30 minutes until the mixture gets syrupy but isn't fully set yet. Don't skip this step or your jell-o will sink through the cream cheese layer and make everything soggy.
While your jell-o cools, toss 2 cups of sliced fresh strawberries with 1 tbsp lemon juice and 1/4 cup granulated sugar. Let this sit for 10 minutes so the berries release their juice — this adds extra flavor to the top layer. Fold these strawberries gently into your partially set jell-o mixture.
Pour the strawberry jell-o mixture over the cream cheese layer and refrigerate for at least 3-4 hours until completely set and firm. I usually make mine the night before so I don't have to worry about timing. Cut into 12 squares and serve cold — this strawberry pretzel salad cozy is best enjoyed within 2 days of assembly.