In a medium bowl, combine the room temperature butter and granulated sugar, then beat together until the mixture is light and fluffy, about 2-3 minutes—this incorporates air and creates a tender cookie texture. Add the vanilla extract and mix until combined. In a separate bowl, whisk together the flour and salt to distribute the salt evenly. Add the dry ingredient mixture to the butter mixture and stir until just combined; don't overmix, as this can develop gluten and make the cookies tough. The dough should come together in loose, crumbly pieces.

Turn the dough out onto a clean surface and gently knead it just a few times to bring it together into a ball. I find that chilling the dough makes it much easier to cut into uniform pieces without the cookies spreading during baking. Flatten the dough into a rectangle (roughly 1/4-inch thick) and wrap it in plastic wrap or transfer it to a parchment-lined baking sheet, then refrigerate for at least 1 hour until firm.

Preheat your oven to 350°F while the dough chills. Once the dough is firm, unwrap it and cut it into cookies using a sharp knife, making each piece roughly 1/2 inch wide—uniform sizing ensures they bake evenly. Arrange the cut cookies on a parchment-lined baking sheet in a single layer, spacing them about an inch apart to allow for even heat circulation.

Place the baking sheet in the preheated 350°F oven and bake for about 20 minutes, until the edges are just barely golden but the centers still look slightly underbaked—they'll firm up as they cool, and this is what keeps shortbread tender and buttery. Remove from the oven and let the cookies cool on the baking sheet for 15-20 minutes before transferring them to a wire rack to cool completely. This resting time allows them to set properly without becoming brittle.

Once the cookies are completely cooled, finely chop the semi-sweet or dark chocolate and melt it in a small saucepan over low heat, stirring frequently to prevent scorching—or use a double boiler method if you prefer extra caution. For easier dipping, transfer the melted chocolate to a small ramekin or shallow bowl. Dip the top of each cooled cookie into the chocolate, allowing excess to drip off, then place it on a parchment-lined plate or baking sheet. I like to let a little chocolate pool on each cookie for a professional-looking finish.

Once all cookies are dipped, refrigerate them for about 20 minutes until the chocolate coating is fully set and firm to the touch. This prevents the chocolate from smudging when you handle the cookies, and it gives them a nice snap when you bite into them.