1. Preheat oven to 375ºF. Grease and flour a 12-cup Bundt pan.
2. In a bowl, whisk flour, baking soda, sugar and salt. In a pan, whisk oil, butter, 2 Tbsp. cocoa, 3 Tbsp. espresso powder, 2 Tbsp. cinnamon and 1 cup water. Bring to a simmer over medium-low heat, stirring. In a bowl, whisk eggs, sour cream and vanilla.
3. Stir cocoa mixture into flour mixture. Fold in egg mixture. Pour into Bundt pan, smoothing top. Bake until a skewer inserted in cake's center comes out clean, 25 to 33 minutes. Let cool on a wire rack for 10 minutes; remove from pan. Let cool completely.
4. Make glaze: Whisk 1/4 tsp. each cocoa, espresso powder and cinnamon. In a heatproof bowl set over 1 inch of simmering water, melt chocolate with butter. Remove from heat; let cool. In a bowl, whisk confectioners' sugar and milk. Stir in chocolate mixture. Drizzle glaze over cake. Sift cocoa mixture over top; let stand until glaze is set.