Preheat the oven according to the cake mix package directions.
Prepare the cake batter using the eggs, oil, and water amounts listed on the box.
Pour the batter into a 9×13 inch baking pan and bake according to the package instructions.
Remove the cake from the oven and let it cool completely in the pan.
Once cool, break the cake into large pieces and transfer to a large mixing bowl.
Use your hands to crumble the cake into fine crumbs with no large pieces remaining.
Add 3/4 cup of the strawberry frosting to the cake crumbs and mix with your hands until combined.
Add the remaining 1/4 cup frosting as needed until the mixture holds together like soft dough.
Fold in the crushed vanilla wafers or graham crackers and the finely crushed freeze-dried strawberries.
Adjust texture if needed by adding a little more frosting for dryness or more crushed cookies for excess moisture.
Line a baking sheet with parchment paper or wax paper.
Use a cookie scoop or spoon to portion 1 to 2 tablespoons of mixture for each truffle.
Roll each portion between your palms to form smooth balls and place them on the prepared baking sheet.
Repeat with all the mixture; you should have about 24 to 30 truffles.
Refrigerate the truffle balls for at least 30 minutes, or freeze for 15 minutes, until firm.
Place the pink candy melts and coconut oil or shortening in a microwave-safe bowl.
Microwave in 30-second intervals, stirring between each, until completely melted and smooth.
Transfer the melted coating to a deep, narrow bowl or cup for easier dipping.
Remove 6 to 8 truffle balls from the refrigerator, leaving the rest chilled.
Place one truffle in the melted pink coating and use a fork to gently turn and fully coat it.
Lift the truffle with the fork, tap the fork on the bowl edge to remove excess coating, and place the truffle on a parchment-lined baking sheet.
Repeat with remaining chilled truffles, working in small batches and reheating the coating briefly if it thickens.
While the pink coating is still slightly wet, sprinkle the tops with crushed freeze-dried strawberries and pink sanding sugar or sprinkles.
Let the pink coating set completely at room temperature for 10 to 15 minutes or in the refrigerator for 5 minutes.
Place the white chocolate or white candy melts in a clean microwave-safe bowl.
Microwave in 30-second intervals, stirring between each, until fully melted and smooth.
Transfer the melted white chocolate to a piping bag or a small zip-top bag and snip a tiny tip off one corner.
Drizzle the white chocolate over the set pink truffles in a back-and-forth or circular pattern.
Allow the white chocolate drizzle to set at room temperature for about 10 minutes.
Serve immediately or store the Strawberry Shortcake Truffles in an airtight container in the refrigerator until ready to serve.