Preheat oven to 350 degrees F (175 degrees C). Grease and flour an 8-inch round springform pan.
Bring a small saucepan of water to a boil. Add dates and cook until softened, about 5 minutes. Drain dates and transfer to a food processor. Puree dates into a smooth paste.
Sift together flour and baking soda into a large bowl. Stir in chopped walnuts until combined and set aside.
Beat together butter and sugar in a large bowl with an electric mixer until light and fluffy. Slowly add beaten eggs, allowing them to thoroughly blend into the butter mixture. Stir in ground dates and mix until combined. Pour in flour mixture and stir with a wooden spoon until just incorporated. Add 3/4 cup hot water or as needed to thin the batter into a pourable consistency. Transfer the batter to the prepared pan.
Bake cake in the preheated oven until a toothpick inserted into the center comes out clean, 45 to 50 minutes. Cool in the pan for 10 minutes before removing to cool completely on a wire rack.