01 - Preheat oven to 350°F. Line two baking sheets with parchment paper for easy cleanup.
02 - Combine chopped dates and boiling water in a small bowl. Stir in baking soda and let stand for 10 minutes until dates soften.
03 - Beat softened butter, dark brown sugar, and granulated sugar in a large bowl until light and fluffy, approximately 2-3 minutes.
04 - Mix in egg and vanilla extract until fully incorporated into the butter mixture.
05 - Whisk together flour, baking powder, and salt in a separate bowl to ensure even distribution.
06 - Add dry ingredients to the wet mixture, mixing just until combined. Fold in the softened date mixture along with all soaking liquid.
07 - Drop tablespoon-sized scoops onto prepared baking sheets, leaving 2 inches of space between cookies to allow for spreading.
08 - Bake for 10-12 minutes until edges are set but centers appear slightly underbaked. Cool on pans for 5 minutes before transferring to wire racks.
09 - Melt butter and brown sugar in a small saucepan over medium heat, stirring until dissolved. Add heavy cream and salt, bring to a simmer, and cook 1-2 minutes until thickened. Remove from heat and stir in vanilla.
10 - Drizzle warm toffee glaze over cooled cookies. Allow glaze to set before serving.