1. Preheat oven to 350°F (175°C). Grease and line an 8-inch round cake pan.

2. Place chopped dates in a bowl and pour hot espresso over them. Stir in baking soda and let sit for 10 minutes.

3. In a medium bowl whisk together flour, baking powder, salt, and cinnamon.

4. In a large bowl beat butter and brown sugar until light and fluffy.

5. Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.

6. Mix the softened date mixture into the butter mixture until combined.

7. Gradually add the dry ingredients and mix until just incorporated.

8. Fold in chopped walnuts.

9. Pour batter into the prepared cake pan and spread evenly.

10. Bake for 35 to 40 minutes or until a toothpick inserted into the center comes out clean.

11. Cool in the pan for 15 minutes before transferring to a wire rack.

12. If desired, whisk together powdered sugar, espresso, and vanilla extract to create the glaze and drizzle over the cooled cake.

13. Slice and serve.