Lightly spray coat of nonstick spray, then butter and flour bottom of bundt pan. Sprinkle chopped pecans onto the buttered pan.
To make the batter, melt chocolate with 1/4 cup water by microwaving it for approximately 30 seconds and stir. In large mixing bowl, add melted chocolate mixture, eggs, oil, cake mix, pudding, and rum. Mix well. Pour batter in bundt pan and cook for 50 to 60 minutes.
To make the primary glaze, gently boil butter, sugar, rum, water and crushed Butterfinger candy bar. When cake is ready, remove from oven and place on foil-covered hot plate. Prick top of cake with fork several times around top. Pour glaze over top of cake, saturating evenly. Use all of the glaze.
Let it sit for 25 to 30 minutes. Get cake plate and put serving side down over top of bundt cake pan, thus inverting cake. Cover cake plate with dome and let sit 4 to 6 hours or overnight.
To make the secondary glaze, melt milk chocolate candy bar, half-and-half, butter, water, and chocolate syrup. Stir well, then heavily drizzle glaze over top of cake and down the sides.
Sprinkle 1/4 cup of crushed peanut butter crunch bar over top and let fall down sides. Serve.
Prepare cake and primary glaze the night before serving.