Saute onions in 1/4 cup butter until translucent. Sift the flour, baking powder, sugar and salt together in a mixing bowl. Stir in the onions and nuts. Beat together the eggs, milk, almond extract, and remaining butter.
Add to the flour mixture and stir until well mixed. Batter may be slightly lumpy. Spoon into a greased 8 x 5 inch loaf pan. Bake in preheated 350 degree oven for an hour. Remove from oven and cool before serving.
Source: Rock Springs Sweet Onion Festival Cook Book 1992