01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - Combine chopped dates and boiling water in a small bowl. Stir in baking soda and let sit for 10 minutes to soften.
03 - In a large bowl, cream the butter, brown sugar, and granulated sugar until light and fluffy.
04 - Beat in the egg and vanilla extract until combined.
05 - In a separate bowl, whisk together the flour, baking powder, and salt.
06 - Add the dry ingredients to the wet mixture and mix just until combined.
07 - Fold in the softened date mixture including any liquid until evenly incorporated.
08 - Drop tablespoon-sized scoops of dough onto the prepared baking sheets, spacing them 2 inches apart.
09 - Bake for 10 to 12 minutes, until edges are set and centers look slightly underbaked. Cool on the pan for 5 minutes, then transfer to a wire rack.
10 - While cookies cool, 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 for 1 to 2 minutes until slightly thickened. Remove from heat and stir in vanilla.
11 - Drizzle the warm toffee glaze over cooled cookies. Allow glaze to set before serving.