Making Apple Walnut Cobbler!

I show how to make this delicious dessert!
Ingredients :
4 cups sliced apples
1 1/2 cups sugar, divided
1/2 teaspoon ground cinnamon
1/2 cup chopped walnuts
1 cup all-purpose flour
1 teaspoon baking powder
1/4 teaspoon salt
1 egg, beaten
1/2 cup half-and-half
1/3 cup melted butter
1/4 cup walnuts (sprinkle on top)