Step 1: Prepare the Crust

1. Crush the Cookies – In a food processor, blend graham crackers (or your chosen cookies) into fine crumbs. Alternatively, place them in a zip-top bag and crush them with a rolling pin.
2. Mix with Butter & Sugar – In a bowl, combine the crumbs, sugar, and melted butter. Stir until the mixture resembles wet sand.
3. Press into the Pan – Firmly press the mixture into the bottom of a 9-inch pie pan, ensuring an even layer. Use the back of a spoon or the bottom of a glass to compact it.
4. Chill or Bake –
   • No-bake option: Place the crust in the refrigerator for at least 30 minutes to set.
   • Baked option: Preheat the oven to 350°F (175°C) and bake for 8–10 minutes. Let it cool completely before adding the filling.

Step 2: Make the Swirl Filling

1. Beat the Cream Cheese – In a large mixing bowl, beat the softened cream cheese until smooth and creamy.
2. Add the Wet Ingredients – Mix in the Greek yogurt (or sour cream), sweetened condensed milk, vanilla extract, and lemon juice. Blend until well combined.
3. Thicken the Filling –
   • If using cornstarch, dissolve it in 2 tbsp of cold milk and mix it into the filling.
   • If using gelatin, dissolve it in ¼ cup of warm water, let it bloom for 5 minutes, then stir it into the mixture.
4. Divide and Color – Split the filling into 3–4 small bowls. Add a few drops of food coloring (or fruit puree) to each, mixing until the colors are vibrant.

Step 3: Create the Swirls

1. Pour the Base Layer – Spread a thin layer of the uncolored filling into the pie crust.
2. Drop the Colors – Spoon different colored mixtures in random spots over the base.
3. Swirl Gently – Using a toothpick or skewer, drag through the colors in a circular or wavy motion to create a marbled effect. Avoid overmixing to keep the colors distinct.

Step 4: Chill and Serve

1. Refrigerate – Cover the pie and chill for at least 4 hours, or preferably overnight, to allow the filling to set.
2. Garnish (Optional) – Before serving, top with whipped cream, pastel sprinkles, white chocolate shavings, or edible flowers for an extra festive touch.
3. Slice and Enjoy – Use a warm knife (run it under hot water and dry it) for clean slices.