Sweet Milk Gravy

Combine granulated sugar and all-purpose flour in a cooking vessel. Blend the ingredients together using a whisk until they form a uniform mixture. Next, incorporate an egg into this mixture by gently folding it in. Subsequently, slowly merge milk into the mixture until it is thoroughly combined. Continue to heat this mixture over high temperature, stirring constantly, until it reaches a rolling boil. Remove the saucepan from the heat source as soon as the mixture thickens and becomes syrupy in consistency. At this point, add vanilla extract to the saucepan and stir until it is fully incorporated. Finally, melt butter into this mixture by stirring it in until it reaches a smooth consistency. Pour the sauce over toasted biscuits or toast and indulge in your delicious treat