Prepare and bake the cake according to package directions in a 9x13 inch pan. Cool completely, then refrigerate for 1 hour.

Crumble the chilled cake into fine crumbs using your hands or food processor. Place in a large mixing bowl.

Beat softened cream cheese with powdered sugar and vanilla until smooth. Add gel food coloring if desired for deeper blue color.

Add cream cheese mixture to cake crumbs and mix thoroughly until evenly combined and mixture holds together when pressed.

Cover bowl with plastic wrap and refrigerate for at least 2 hours or overnight.

Prepare coating by combining shredded coconut with granulated sugar in a shallow bowl. Add blue food coloring and mix until evenly tinted.

Line a baking sheet with parchment paper. Use a small cookie scoop to portion out mixture and roll into 1-inch balls.

If using white chocolate, melt it and dip each ball, allowing excess to drip off. Immediately roll in blue coconut mixture.

Place coated truffles on prepared baking sheet and refrigerate for at least 30 minutes to set.

Let truffles sit at room temperature for 10-15 minutes before serving for best texture.