In a large bowl, combine the granulated sugar and lemon zest. Rub them together with your fingers until fragrant and the sugar turns slightly yellow.

Add the softened butter and brown sugar to the infused sugar. Cream together on medium-high speed for 3-4 minutes until light and fluffy.

Beat in the eggs one at a time, followed by the vanilla extract and lemon juice, mixing until just combined.

In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined.

Toss the frozen raspberries with 1 teaspoon of flour. Gently and quickly fold the frozen raspberries into the dough using a rubber spatula.

Cover the bowl tightly and chill the dough in the refrigerator for at least 2 hours.

Preheat the oven to 350°F (175°C) and line two baking sheets with parchment paper.

Scoop 2 to 3-tablespoon-sized balls of dough onto the baking sheets, spacing them 2 inches apart.

Bake for 11-13 minutes until the edges are lightly golden but the centers remain soft.

Immediately sprinkle the hot cookies with flaky sea salt and extra lemon zest. Let cool on the pan for 5 minutes before transferring to a wire rack.