In a small heatproof bowl whisk together cocoa powder and sugar. Add hot water and whisk until smooth. Stir in butter until melted, then whisk in vanilla. Keep warm.

Strawberry Sauce

Cook strawberries

Place strawberries, sugar, and lemon juice in a small saucepan over medium heat. Cook, stirring occasionally, until berries break down and sauce thickens slightly, 6–8 minutes. If too thick, add up to 1 tablespoon water. Remove from heat and let cool slightly; mash with a fork for a chunky sauce or pulse briefly in a blender for smooth.

Caramel Sauce

Make caramel

In a medium saucepan over medium heat, melt the 1/2 cup sugar, stirring frequently with a wooden spoon. Once it becomes an amber liquid (watch carefully to prevent burning), immediately add the cubed butter and whisk until incorporated. Slowly pour in the warm heavy cream while whisking (mixture will bubble vigorously). Remove from heat and stir in sea salt. Let cool slightly to thicken.

Optional Huckleberry Topping

Prepare huckleberry topping

In a small saucepan combine huckleberries, sugar, and lemon juice. Cook over low–medium heat, stirring, until berries release juices and sauce thickens slightly, 4–5 minutes. Remove from heat and let cool. Use as an alternate topping or spoon over the sundae in addition to other sauces.

Assemble Sundae

Scoop three generous scoops of vanilla ice cream into a chilled bowl or sundae glass.

Drizzle 1–2 tablespoons of chocolate sauce over one scoop, 1–2 tablespoons of strawberry sauce over the second scoop, and 1–2 tablespoons of caramel sauce over the third scoop. If using huckleberry topping, spoon 1 tablespoon over any scoop or serve on the side.

Top the sundae with about 2 tablespoons whipped cream, sprinkle chopped nuts if using, and finish with a maraschino cherry.

Serve immediately.