Preheat oven to 350°F (175°C). Line two baking sheets with parchment paper. In a medium bowl whisk together the all-purpose flour, baking soda, and salt; set aside.

Cream butter and sugars

In a large bowl or bowl of a stand mixer, beat the softened unsalted butter, granulated sugar, and light brown sugar on medium speed until light and fluffy, about 2–3 minutes.

Add eggs and vanilla

Add eggs one at a time, mixing after each until incorporated, then beat in the vanilla extract until smooth.

Combine wet and dry

Reduce speed to low and gradually add the flour mixture, mixing just until combined. Scrape down the bowl as needed to ensure even mixing.

Fold in chocolate chips

Using a spatula, fold in the semisweet chocolate chips until evenly distributed through the dough.

Portion and bake

Drop rounded 2-tablespoon portions (about golf-ball size) of dough onto the prepared baking sheets, spaced 2 inches apart. Bake for 10–12 minutes, or until edges are set and centers are still soft. For softer cookies remove at 10 minutes; for slightly crisp edges take to 12 minutes.

Cool and crumble

Allow cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely. Reserve 2 cups of cookies (about 6–8 cookies depending on size) and break or pulse in a food processor to make crumb pieces for assembly. (If you prefer toasted crumbs, toss crumbs with 1 tablespoon melted butter and toast on a baking sheet at 350°F/175°C for 6–8 minutes until fragrant.)

Sundae components

Prepare sauces if needed

If using store-bought sauces, gently warm the hot fudge and caramel in a small saucepan over low heat or microwave in 15–20 second intervals until pourable but not boiling. Stir to smooth.

Scoop ice cream

Scoop the vanilla ice cream into 6 serving bowls or sundae glasses. Use about 3 generous scoops per serving (roughly 1.5 cups ice cream per serving).

Assembly and garnish

Layer and drizzle

Divide half of the cookie crumbs among the sundae bowls, sprinkling them over the ice cream scoops. Drizzle each sundae with about 2 tablespoons hot fudge and 1 tablespoon caramel (adjust to taste).

Add more cookie and toppings

Top each sundae with another sprinkle of cookie crumbs (about 2–3 tablespoons), a generous dollop of whipped cream (about 1/3 cup per serving), a sprinkle of chopped toasted nuts (about 2 tablespoons per serving), and finish with a maraschino cherry. If desired, finish with a light pinch of sea salt to enhance flavors.

Serve immediately

Serve sundaes immediately while the sauces are warm and the cookies retain some texture. Leftover baked cookies can be stored in an airtight container for up to 3 days; assembled sundaes are best eaten right away.