Preheat your oven to 350°F (175°C). Prepare your 9x13 inch baking pan by greasing it or lining it with parchment paper for easy removal.
In a small saucepan, combine the unwrapped baking caramels and milk over low heat. Stir frequently until the caramels are completely melted and smooth. Set this mixture aside to cool slightly.
In a large mixing bowl, combine the German chocolate cake mix, fudge brownie mix, eggs, water, and canola oil. Use a whisk to mix until just combined; be careful not to overmix.
Fold in 1 cup of chopped pecans into the cake batter, ensuring they are evenly distributed.
Pour half of the cake batter into the prepared baking pan, spreading it evenly. Drizzle the melted caramel mixture over the batter, then gently pour the remaining batter on top. Use a spatula to spread it evenly.
Bake the cake in the preheated oven for 30-35 minutes or until a toothpick inserted into the center comes out clean. Once baked, remove from the oven and allow it to cool completely in the pan.
In a double boiler or microwave, heat the heavy whipping cream until it just begins to simmer. Remove from heat and add the semisweet chocolate morsels. Let it sit for a minute, then stir until the chocolate is completely melted and the ganache is smooth.
Once the cake is cooled, pour the ganache over the top, allowing it to drip down the sides. Sprinkle the remaining chopped pecans and the chopped turtle candies over the ganache for an extra indulgent finish.
Allow the ganache to set slightly before slicing. Serve at room temperature or slightly chilled for a perfect dessert experience. Enjoy your Turtle Cake with a scoop of vanilla ice cream for an unforgettable treat!