Preheat the oven to 350°F (180°C) and grease a 9-inch (23cm) round cake pan with butter.

In a mixing bowl, cream together the butter and sugar until light and fluffy.

Beat in the eggs, one at a time, until well combined.

In a separate bowl, sift together the flour, baking powder, baking soda, and salt.

Gradually add the dry ingredients to the butter mixture, alternating with the sour cream.

Stir in the mandarin orange juice and zest until well combined.

Fold in the chopped mandarin oranges.

Pour the batter into the prepared cake pan and smooth the surface.

Sprinkle the sliced almonds on top of the batter.

Bake for 35-40 minutes, or until a toothpick inserted into the center of the cake comes out clean.

Let the cake cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.