Grease a 12 cup Bundt pan with Crisco or spray with nonstick baking spray and lightly flour. Set aside.
Beat the softened butter in a mixer until creamy. Add sugars, beating until fluffy. Add eggs, one at a time, beating well after each addition. In a medium bowl, combine flour, baking powder, and salt. Gradually add flour mixture to butter mixture in thirds, alternately with milk, beginning and ending with flour mixture. Beat until just combined. Don’t overmix. Stir in toffee bits and pecans.
Pour batter into prepared pan.
Bake until a toothpick inserted near the center of cake comes out clean, 80 to 85 minutes.
Let cake cool in pan for 30 minutes. (Yes, this is important so that the cake won’t fall apart when you remove it from the pan.)
Remove from pan, and let cool completely on a wire rack. While the cake is cooling for the last 10 minutes, make the Caramel Drizzle.
Caramel Drizzle Instructions
In a medium saucepan, combine condensed milk and brown sugar; bring to a boil over medium-high heat, whisking/stirring constantly.
Reduce heat, and SIMMER for 5 minutes, BUT whisking constantly.
Remove from heat; whisk in butter and vanilla.
Drizzle the Caramel over cooled cake immediately. You will want to drizzle the caramel while it’s still hot because it will harden a bit when cooled and make it harder to pour.