Whisk the flour, cinnamon, baking soda, and salt together in a medium bowl. Set aside.

Add the softened butter, ½ cup granulated sugar, and brown sugar to a large mixing bowl. Beat with an electric mixer on medium speed for 1 to 2 minutes, or until light and creamy.

Beat in the egg and vanilla until everything is well combined.

Add the flour mixture and stir until a soft dough forms. Use your hands to gently bring the dough together into a ball if needed. Wrap tightly in plastic wrap and refrigerate for 1 hour.

While the dough chills, add the chopped dates, remaining ¼ cup granulated sugar, and water to a small saucepan. Bring to a boil over medium heat, then reduce the heat to low.

Simmer for about 5 minutes, stirring often, until the dates are very soft and the mixture has cooked down to a thick, spreadable paste.

Stir in the chopped pecans and remove from the heat. Let the filling cool completely before assembling the cookies. Don't rush this part. Warm filling and buttery cookie dough are not friends.

Place the chilled dough on a lightly floured sheet of wax paper or parchment paper. Roll it into a rectangle about 12 x 8 inches.

Spread the cooled date filling evenly over the dough, leaving about ½ inch uncovered around the edges.

Starting with one long side, carefully roll the dough into a tight log, using the paper to help lift and guide it as you roll.

Wrap the log tightly in wax paper or plastic wrap and refrigerate for at least 1 hour. For the neatest pinwheels and easiest slicing, refrigerate overnight.

When you're ready to bake, preheat the oven to 375°F. Line baking sheets with parchment paper.

Unwrap the chilled dough and use a sharp knife to cut it into ¼-inch slices. If the log begins to soften while you're slicing, pop it back into the refrigerator for 10 to 15 minutes.

Arrange the cookies on the prepared baking sheets, leaving a little space between them.

Bake for 9 to 12 minutes, just until the edges are lightly golden and the centers are set. Don't overbake them if you want that tender, old-fashioned texture.