Melt the blue candy melts and dip the tops of the sugar cones to coat. Let any excess drip off, then place the cones on parchment paper to set.
In a large mixing bowl, whip the heavy cream until stiff peaks form.
In a separate bowl, stir together the sweetened condensed milk and vanilla extract. Add a few drops of blue gel food coloring until the mixture resembles bright ocean water.
Gently fold the whipped cream into the blue base until smooth and fluffy.
Pour half of the ice cream mixture into a loaf pan and sprinkle with chopped vanilla cookies for crunch.
Layer the rest of the ice cream mixture on top. Drizzle strawberry preserves over the surface and gently swirl with a knife for that signature shark bite effect.
Cover the pan and freeze for at least 6 hours, or overnight, until firm.
To serve, spoon a handful of blue candies into sundae glasses, then add scoops of the homemade ice cream. Top with a dipped cone, a few gummy sharks, and extra cookie crumbles if you’d like.