Preheat the oven to 350°F. Line baking sheets with parchment paper.

In a small bowl, whisk together the flour, baking soda, and salt.

In a medium mixing bowl, or the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugars on medium speed until smooth and fluffy, about 2 minutes. Scrape down the bowl. Beat in the egg and vanilla until well combined.

Add the flour mixture and beat on low speed until combined, stopping to scrape down the sides of the bowl once during mixing. Add dates, red and green cherries, candied pineapple, and chopped nuts, mix until fully combined. Scoop the dough by the heaping tablespoon, and place on the prepared baking sheets about 2 inches apart.

Bake, one sheet at a time, until golden brown and centers are still slightly shiny, 8 to 10 minutes. Let cool slightly on the pan before moving to a wire rack to cool completely. Store in an airtight container for up to 1 week.