Prep the oven. Preheat the oven to 350ºF. Generously grease your loaf pan using butter or cooking spray.
Combine the dry ingredients. In a medium mixing bowl, sift together the cake flour, vanilla pudding mix (in dry powdered form), baking powder, and salt.
Combine the wet ingredients. In a larger mixing bowl, whip together the butter, sugar, eggs, and almond extract for a few minutes, until the mixture turns light yellow.
Mix the cake batter. Beat in half of the milk and half of the sifted flour mixture, then beat in the remaining milk and flour mixture. Whip until the batter is smooth and creamy. Rinse and dry the medium mixing bowl that you used for the sifted flour; you’ll need it again soon.
Make it chocolatey. In a small bowl, whisk together the cocoa powder and 1/3 cup of very hot water until smooth. Pour a little less than half of the prepared vanilla cake batter into the medium mixing bowl that you rinsed out. Whisk in the cocoa powder mixture till fully combined and smooth. This is your chocolate marbling batter. Reserve the rest of the batter, as this is your light cake marbling batter.
Assemble. Alternate adding the light and dark cake batters into your loaf pan. Then, use a toothpick or a knife to swirl the two batters together to marble them.
Bake. Bake the marble cake at 350 degrees for 45-55 minutes, or until a toothpick inserted in the center comes out clean.
Cool. Remove from the oven and cool in the pan on a wire rack for 10-15 minutes. Gently remove the cake from the pan and let it cool completely on the rack.
Notes
This cake will keep at room temperature for 3-4 days. Wrap in plastic wrap or foil to seal in the moisture, or keep it inside an airtight container.
To extend shelf life, keep the cake in the refrigerator.