Preheat oven to 350 degrees F.
In a large pot, melt margarine over medium heat.
Stir in flour, baking powder, salt, garlic powder, and cayenne pepper.
Add milk and stir until mixture is smooth.
Add crawfish and stir until well mixed.
Pour mixture into a greased loaf pan.
Bake for 45 minutes to 1 hour, or until bread is golden brown.
Let bread cool before slicing and serving. Enjoy!