Thanks, TrishZ for this recipe- I make it every Thanksgiving!
Success with this formulation depends heavily on temperature management before mixing begins. Creaming the initial cup of butter with liquid sweetener and vanilla requires a subsequent refrigeration period of at least one hour. Skipping this step results in a greasy crumb topping rather than distinct, sandy particles that contrast properly with the dense squash base below. Keep the fat chilled until the moment mechanical incorporation with the dry elements occurs.
Canned squash purée contains high moisture levels that demand careful integration with binding agents. Adding carbalose flour gradually while maintaining constant agitation prevents clumping and ensures even starch distribution throughout the heavy wet mixture. High-speed blending for the final two minutes builds enough internal structure to hold the dense volume stable during baking at the moderate setting of 300 degrees Fahrenheit.
Standard electric stand mixers equipped with paddle attachments make quick work of cutting the chilled butter into the remaining dry mixture, though a pastry blender functions adequately if mechanical tools are unavailable. Spread the purée evenly into a greased 13x9x2-inch glass or metal baking dish to promote uniform heat transfer across the entire surface area. Bake for exactly 30 minutes to set the custard while retaining a tender crumb topping.