Position an oven rack in the bottom third of the oven and preheat the oven to 350 F. Prepare muffin tin by lining with 12 cupcake liners, lightly grease with oil (butter) or spraying with non-stick spray.
Cupcake Preparation: Sift together the flour, Clabber Girl Baking Powder, Clabber Girl Baking Soda, and salt. Using an electric mixer at high speed, beat the butter in a large bowl for about 1 minute until smooth. Mix in the agave syrup or honey (don't worry if the mixture looks curdled) vanilla, and gradually beat in the eggs (which will help the butter mixture emulsify).
Reduce the mixer speed to low. Starting with the flour mixture, add three equal portions of the flour, alternating with two equal portions of the yogurt, increasing the speed to high for a few seconds beating mixture smooth after each addition. Be sure to scrape the sides of the bowl often during mixing. When the batter is smooth, add the orange zest and return the mixer speed to high and whip for about 20 seconds.
Divide batter evenly among the prepared cups. Bake about 25 to 30 minutes or until a toothpick inserted in the center comes out clean. Let pan cool on a wire cake rack for 5 minutes. Remove the cupcakes from the pan, transfer to the rack, and let cool completely.
Icing Preparation: Add the mascarpone to a small bowl. Use a rubber spatula to stir in the agave syrup or honey until blended, add orange juice, and combine. Finish the tops of the cupcakes with the icing. Garnish with freshly grated orange zest and the strawberries. Store cupcakes at room temperature. Best served the day they are made!