Preheat the oven to 325 degrees F. Grease and flour a 10-inch Bundt pan with cooking spray. Sprinkle ½ cup chopped nuts evenly over the bottom of the pan.
Combine cake mix and pudding mix in a large bowl. Beat in eggs, Bailey’s Irish cream, oil, and water with an electric mixer on high speed (or stand mixer on medium) for 5 minutes. Pour batter over nuts in the bottom of the pan.
Bake the cake until a toothpick inserted into the center of the cake comes out clean, about 1 hour. Let the cake cool in the pan for 10 minutes, then flip the cake over. Allow to rest for 10 more minutes, and then poke about 6 holes in the top of the cake using the end of a wooden spoon. Last step, prick the top and sides of the cake with a toothpick, all over the cake to add more (small) holes.
To make the glaze:
Next make the glaze by combining sugar, butter, and water in a small saucepan. Bring to a boil and boil for 5 minutes, stirring constantly. Remove from heat and stir in the Bailey’s Irish cream and vanilla extract.
Pour the glaze into the bottom of the bundt pan and put the cake back into the pan. Allow to sit for another 20 minutes and then flip it over, inverting the cake onto a serving plate. All the glaze will be absorbed into the cake.
Top with remaining ¼ cup of chopped pecans and serve!