In a large mixing bowl, sift together the flour, cocoa powder, baking powder, baking soda, and salt. In a separate bowl, cream the butter and sugar until light and fluffy, about 3–5 minutes. Add the eggs one at a time, mixing well after each addition, then stir in the milk and vanilla extract. Gradually incorporate the dry ingredients until combined, creating a smooth, rich batter for your German Chocolate Roll Cake.

Preheat your oven to 350°F (175°C) and line a half-sheet pan (about 18x13 inches) with parchment paper, ensuring it extends over the edges for easy removal. Spread the prepared batter evenly across the pan, smoothing the top with a spatula. Bake for 15–18 minutes, or until a toothpick inserted in the center comes out clean.

Once baked, remove the cake from the oven and let it cool for about 5 minutes. Carefully invert the cake onto a damp kitchen towel lined with more parchment paper. Starting from one edge, gently roll the cake with the towel, creating a log shape. Allow the roll to cool completely in this shape for about 30 minutes.

While the cake cools, combine the shredded coconut, chopped pecans, sugar, and milk in a medium saucepan over medium heat. Stir continuously for about 5–7 minutes until the mixture thickens slightly. Remove from heat and allow the frosting to cool for a few minutes.

After the cake has cooled completely, gently unroll it from the towel. Carefully spread the prepared frosting evenly over the surface of the cake, ensuring a generous layer that reaches the edges. Roll the cake back up, using the parchment paper to assist.

Once rolled, place the German Chocolate Roll Cake seam-side down on a serving platter. Sprinkle additional shredded coconut and chopped pecans on top. Chill for about 15 minutes to set the frosting before slicing into beautiful pieces.