Preheat oven to 350 degrees Fahrenheit.

In a large mixing bowl, combine 3 cups of flour, 1 cup of whole wheat flour, 1/2 cup of sugar or Splenda, 2 teaspoons of baking soda, and 1 teaspoon of salt.

Cut in 4 tablespoons of butter until the mixture resembles pea-sized clumps.

Stir in 1 cup of dried currants and 1 1/2 cups of low-fat plain yogurt.

Turn the dough onto a floured cutting board.

Knead for 1 minute.

Shape the dough into a round loaf.

Slice an 'X' on the top of the loaf.

Bake on a greased baking sheet for 45-50 minutes, or until golden brown.