Preheat the oven to 325 degrees F (160 degrees C).
Place 1/4 cup of Pecans (1/4 cup) in a food processor and pulse until fine.
Spray a pan with Nonstick Cooking Spray (to taste). Add the pecan crumbs to the pan and dust all sides.
Toast remaining cup of Pecans (1 cup) the oven until lightly browned. Remove from oven and roughly chop pecans.
Add Unsalted Butter (1/2 cup) and cook over medium heat for 6-8 minutes swirling occasionally, until milk solids start to turn a golden to golden brown color, remove from heat.
Set aside to cool for 5-10 minutes.
Combine All-Purpose Flour (2 cup), Granulated Sugar (1 1/2 cup), Instant Vanilla Pudding (1 package), Baking Powder (2 teaspoon), and Salt (1 teaspoon). Whisk to combine. Add Egg (4), Canola Oil (1/2 cup), and Milk (1/2 cup). Beat for 2 minutes.
Add browned butter to the mixture beat on medium speed. Add Rum (1/4 cup) and Passion Fruit Nectar (1/3 cup) and beat for 1 minute.
Transfer the batter to the prepared cake pan and bake for 50-60 minutes in the center of the oven.
Remove the cake from oven and allow it to cool for 10-15 minutes.
To make the syrup, in a saucepan, melt Unsalted Butter (1/2 cup) with Granulated Sugar (1 cup) and Water (1/4 cup), stirring until the sugar is dissolved. Add the White Rum (1/4 cup) and Passion Fruit Nectar (1/3 cup) and simmer for a few minutes until it becomes syrupy.
While the cake remains in the pan, use a skewer to poke holes all over the cake. Pour the syrup over the cake, dabbing with a pastry brush until it's been absorbed. Place the cake (in the pan) into the refrigerator overnight.
To make the glaze (optional), mix the Powdered Confectioners Sugar (1/2 cup) with Milk (2 tablespoon) and stir until smooth. Drizzle glaze over the cake.