1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and line a 15×10-inch jelly roll pan with parchment paper.
2. Mix the Dry Ingredients: In a large mixing bowl, combine 1 cup all-purpose flour, 1/2 cup unsweetened cocoa powder, 1 cup granulated sugar, 1 teaspoon baking powder, 1/2 teaspoon baking soda, and 1/4 teaspoon salt. Whisk until well combined.
3. Add Wet Ingredients: Add 3 large eggs, 1 teaspoon vanilla extract, and 1/4 cup boiling water to the dry mixture. Beat until the batter is smooth and well blended.
4. Spread the Batter: Pour the batter into the prepared jelly roll pan, spreading it evenly. Bake for 12-15 minutes, or until a toothpick inserted in the center comes out clean.
5. Cool the Cake: Remove from the oven and allow to cool slightly. While it’s still warm, gently roll the cake in the parchment paper starting from one of the short ends. Let it cool completely in this rolled position.
6. Prepare the Filling: In a bowl, mix 1 cup caramel sauce with 1/2 cup toasted pecans. Fold in 1 cup whipped cream until combined for a fluffy filling.
7. Unroll the Cake: Once cooled, carefully unroll the cake and remove the parchment paper. Spread the filling evenly over the cake, leaving a small border around the edges.
8. Roll the Cake: Starting from the edge, tightly re-roll the cake. Wrap it in plastic wrap and refrigerate for at least 1 hour to set.
9. Prepare the Ganache: In a small saucepan, heat 1/2 cup heavy cream until just simmering. Pour over 1 cup semi-sweet chocolate chips in a bowl. Let sit for 2 minutes, then stir until smooth.
10. Finish the Cake: Remove the cake roll from the refrigerator, unwrap it, and place it on a serving platter. Drizzle the chocolate ganache over the top. Optionally, sprinkle more toasted pecans for garnish.

Throughout each step, keep an eye on the texture of the cake mixture and the ganache. For best results, ensure the cake is fully cooled before spreading the filling to avoid melting it.