In a medium bowl, cream together the butter and sugar. Stir in the eggs and vanilla. Combine the flour, baking powder, and salt; stir into the creamed mixture. Divide dough equally into three small bowls. Add almond extract and red food coloring to one portion; stir until thoroughly mixed. Mix chocolate into second bowl, and walnuts into the third bowl.
In a medium bowl, cream together the butter and sugar. Stir in the eggs and vanilla. Combine the flour, baking powder, and salt; stir into the creamed mixture. Divide dough equally into three small bowls. Add almond extract and red food coloring to one portion; stir until thoroughly mixed. Mix chocolate into second bowl, and walnuts into the third bowl.
Layering distinct dough portions inside a 9x5-inch loaf pan requires physical restraint to prevent the strata from merging unevenly. Pressing each section firmly against the previous layer eliminates air pockets that cause structural failure during slicing. Chilling the compacted block for four full hours solidifies the butter sufficiently to yield under a sharp chef's knife without crumbling. Operating with a chilled block prevents the chocolate, walnut, and almond-tinted layers from smearing across one another when cut into quarter-inch slices. Spacing the portions one inch apart on the baking sheet accommodates the modest expansion driven by the baking powder.