Preheat the oven to 350 degrees F (175 degrees C).
Cream brown sugar, butter, and yogurt together in a bowl. Add eggs one at a time, beating after each addition. Beat in vanilla extract.
Dissolve baking soda in hot water and add to the batter. Stir in cake flour, whole wheat flour, and salt, being careful not to overmix. Stir in dark chocolate chips, semisweet chocolate chips, and walnuts.
Drop spoonfuls of dough 2 inches apart onto ungreased baking sheets.
Bake in the preheated oven until edges are golden, 10 to 12 minutes. Cool on the baking sheets for 5 minutes before removing to a wire rack to cool completely.