Separate eggs; set aside.
Cut kernels from cob, using sharp blade then back of blade to scrape off some of the pulp and juice.
Mix corn with cheese.
Preheat oven to 350°F and place oven rack somewhat low for baking.
Combine biscuit mix, mustard, chili powder and salt in a saucepan and very gradually stir in milk.
Place over moderate heat and when hot, stir in cheese and corn mixture.
Add a little of this hot sauce to egg yolks, stirring constantly.
Return all to saucepan, stir until hot, then remove from heat.
Let rest.
Add baking powder to egg whites and beat to soft peaks; gently fold into corn mixture.
Pour into ungreased 1 1/2 quart casserole.
Place in larger pan of warm water then onto oven rack to bake for 55 minutes.
Test with point of knife inserted in center of souffle it should come out clean.