Preheat your oven to 350°F (175°C).

In a mixing bowl, combine crushed pretzels, melted butter, and granulated sugar. Mix until evenly coated.

Press the pretzel mixture firmly into the bottom of a 9x13-inch baking dish to form the crust. Bake for 8-10 minutes, then let it cool completely.

In another bowl, beat the softened cream cheese and powdered sugar until smooth.

Fold the thawed whipped topping into the cream cheese mixture until fully combined.

Spread the cream cheese mixture evenly over the cooled pretzel crust, ensuring you cover the entire surface. Place the dish in the refrigerator to chill while you prepare the top layer.

In a separate bowl, dissolve the strawberry-flavored agar powder in 2 cups of boiling water. Stir until fully dissolved, then add 1 cup of cold water and mix well. Let the mixture cool slightly but not set.

Arrange the sliced strawberries evenly over the cream cheese layer.

Carefully pour the cooled agar mixture over the strawberries. Ensure the liquid covers the strawberries evenly.

Refrigerate the dish for at least 4 hours, or until the top layer is fully set.

Once set, slice and serve chilled.