Mix cake mix, eggs, oil, and milk well. Beat until smooth.

Pour into greased and floured 12” x 18” cookie sheet and bake at 350°F for about 20 minutes. Cool 3 – 4 minutes.

In large bowl, pour melted butter and vanilla over combined remaining dry ingredients. Use fork or spoon to blend — Do not over-mix or it will make smaller crumbs.

With spoon, cover entire top of cake with crumbs. Press into cake.

Bake for 20 minutes longer. Cool slightly and sprinkle with powdered sugar.