Dulce de Leche and Chocolate Chunk Bread Pudding

Ingredients:
8 1/2-inch-thick slices egg bread (about 4 x 5 inches), crusts trimmed, cut into ¾" to 1" cubes
4 Tbsp (½ stick) unsalted butter, melted, divided
1½ cups heavy whipping cream
1 cup dulce de leche ice cream topping or butterscotch-caramel sauce plus more for serving
4 large eggs
2 large egg yolks
2 Tbsp dark rum
1 tsp vanilla extract
Pinch of salt
½ cup (about 3 ounces) bittersweet chocolate chips
2 Tbsp sugar
Powdered sugar

Method:

1. Preheat oven to 180°C.
2. Place bread in large bowl. Drizzle with 3 tablespoons melted butter; toss. Transfer to rimmed baking sheet. Bake until bread begins to color, stirring occasionally, about 12 minutes. Cool. Brush 11"x7"x2" glass baking dish with 1 Tbsp melted butter.
3. Stir whipping cream and 1 cup dulce de leche in medium saucepan over medium heat until blended and bubbling. Remove from heat. 
4. Whisk eggs and yolks in large bowl. Add rum, vanilla, and salt; gradually whisk in warm dulce de leche mixture. 
5. Stir in bread cubes. Let soak 30 mins, stirring occasionally.
6. Mix chocolate chips into custard mixture. Pour into prepared dish. Sprinkle with 2 tablespoons sugar. 
7. Bake pudding until puffed and set in center, about 35 mins. Let cool 15 mins. Dust with powdered sugar.
8. Serve warm, passing more dulce de leche topping alongside.