Preheat oven to 350 degrees. Prepare mini baking loaf pans (I used 3 5"x 3" ceramic loaf pans) by spraying with non-stick cooking spray.
In the bowl of a stand mixer beat butter and sugar until fluffy.
Add one egg at a time, beating after each addition.
Add coffee granules and vanilla extract; mix until most of the crystals have dissolved, about 3-4 minutes. Beat in melted white chocolate until smooth.
In a medium bowl, whisk together flour, salt, baking powder and baking soda.
Add half of the dry mixture to the wet mixture and mix until it just disappears.
Add Greek yogurt and mix until just combined. Add remaining flour mixture and beat until just incorporated (do not over-mix).
Pour ⅓ of the batter into each greased loaf pan. Place the loaf pans onto a baking pan (to catch leaks if they overflow), and bake for about 35-40 minutes or until a skewer inserted in the center comes out clean. Cool completely.
Make Icing: Add a teaspoon of water to powdered sugar and mix. Slowly add in about ¼ teaspoon of additional water and stir until the icing reaches desired consistency. Set aside.
When pound cakes are completely cool, drizzle with icing. While the icing is wet, sprinkle with coarse sanding sugar and adhere decorative embellishments if desired. Allow the icing to set before wrapping.