Step 1: Prep Your Pan & Preheat Oven: Generously grease a 9-inch or 10-inch Bundt pan or a 10-cup tube pan with shortening or butter, then lightly flour, tapping out excess. Preheat your oven to 325°F (160°C).
Step 2: Combine Dry Ingredients: In a medium bowl, whisk together the all-purpose flour, unsweetened cocoa powder, baking soda, and salt. Set aside.
Step 3: Cream Butter & Sugar: In a large mixing bowl, using an electric mixer, cream together the softened unsalted butter and 2 cups granulated sugar until light, fluffy, and pale in color (about 3-5 minutes).
Step 4: Add Eggs Gradually: Beat in the room temperature eggs one at a time, mixing well after each addition until fully incorporated. Scrape down the sides of the bowl as needed.
Step 5: Incorporate Wet Ingredients: In a separate small bowl, whisk together the sour cream, vegetable oil, and 1 teaspoon vanilla extract until smooth.
Step 6: Alternate Dry & Wet: With the mixer on low speed, gradually add the dry ingredients to the butter mixture, alternating with the sour cream mixture. Begin and end with the dry ingredients. Mix just until combined; do not overmix!
Step 7: Pour & Bake: Pour the batter evenly into your thoroughly prepared Bundt or tube pan. Bake for 1 hour 15 minutes to 1 hour 30 minutes, or until a wooden skewer inserted into the thickest part of the cake comes out clean or with a few moist crumbs attached.
Step 8: Cool the Cake in Pan: Let the cake cool in the pan on a wire rack for 15-20 minutes.
Step 9: Invert & Finish Cooling: Carefully invert the cake onto a wire rack to cool completely before frosting.
Step 10: Prepare the Coconut-Pecan Frosting: In a medium saucepan, combine evaporated milk, 1 1/2 cups granulated sugar, egg yolks, and 1/2 cup unsalted butter. Cook over medium heat, stirring constantly, until the mixture thickens significantly and coats the back of a spoon (10-12 minutes). Remove from heat.
Step 11: Finish Frosting: Stir in 1 teaspoon vanilla extract, shredded coconut, and chopped pecans into the cooked mixture. Let the frosting cool slightly; it should be warm but not hot when applied to the cake.
Step 12: Frost Your Masterpiece: Once the cake is completely cool, spoon the warm coconut-pecan frosting generously over the top of the cake, allowing it to drip down the sides. Spread evenly as desired.
Step 13: Serve & Enjoy: Slice and serve! Store any leftovers in an airtight container at room temperature.