Cooked Starter: Combine all ingredients in small saucepan. Cook on medium heat, whisking constantly, until the whisk leaves a trail on the bottom of the pan, about 5 min. Cool to room temperature.
Dough: Warm milk to 90°F. Sprinkle yeast over milk. Let stand while assembling remaining dough ingredients.
Combine flour, sugar and salt in bowl of mixer fitted with dough hook. Stir in eggs, milk mixture and cooked starter. Mix on low speed until smooth, about 4 min. Add butter. Mix on medium speed 10 min. (Dough will be tacky.) Mix in NILLA Wafers just until blended.
Place dough in large greased bowl, turning to coat entire surface. Cover with plastic wrap. Let rise at room temperature 1 hour. Turn dough onto lightly floured surface. Deflate and shape into a rectangle to fit a 13 x 4 x 4-inch Pullman Loaf Pan. Remove dough from bowl. Let dough rest 15 min. Place dough in greased pan. Cover pan with lid. Proof 45 min. or until dough is 3/4th of the height of the pan.
Bake in 350°F standard oven 35 min. Remove lid; bake an additional 10 to 15 min. or until internal temperature registers 200 to 205°F. Cool in pan on wire rack 15 min. Remove from pan and cool completely.
Tiramisu Cream: Mix mascarpone, powdered sugar and extracts in large bowl until smooth. Gently fold in whipped cream. Refrigerate until ready to use.
Banana Topping: Cut bananas lengthwise into quarters, then cut into 1/2-inch-thick slices. Melt butter in sauté pan; add bananas. Cook 1 min. Add caramel sauce and heat just until warm.
For each serving: Cut a 1-1/2-inch thick slice from Banana Brick Bread. Use 1-3/4-inch round cutter to remove a circle from center of bread slice. (Reserve center for another use or discard).
Place bread slice under broiler 1 to 1-1/2 min. or until light golden brown. Turn and brown other side. Transfer to serving plate.
Fill center with 2.5 oz. Tiramisu Cream. Spoon 3.75 oz. Banana Topping over bread and onto plate. Sprinkle with 1/2 oz. cookie pieces.