1. Preheat oven to 350°F.  Line 2 muffin tins with 16 liners, 8 in each, filling remaining slots halfway with warm water. 

2. In a large mixing bowl, whisk together flour, ½ cup cocoa, baking powder, baking soda and salt. Set aside. 

3. In a stand mixer fitted with a  paddle attachment or in a large bowl using a handheld electric mixer, beat eggs, cane juice and oil on medium high until pale yellow in color and doubled in volume, 2 to 3 minutes. Reduce speed to low and add sour cream, ½ cup milk and vanilla and  beat until combined. Stop machine  and add flour mixture. Mix on low until combined, then beat  on medium-high for 2 minutes. Divide batter among liners, filling  each two-thirds full. Bake until a  toothpick inserted in the center  comes out with fudgy crumbs, 10 to 12 minutes, being mindful not to over bake. Transfer cupcakes to  a wire rack to cool completely. 

4. Meanwhile, in a food processor, process dates and butter until  smooth, 4 to 5 minutes. Add remaining ¼ cup cocoa and espresso powder and process until combined. Add remaining 3 tbsp milk, 1 tbsp at a time, scraping down sides  after each addition. Once milk is incorporated, process for an additional 2 minutes. Spread icing over cupcakes.