Center a rack in the oven and preheat the oven to 350°F (175°C). For a convection oven, reduce cooking temperature by 25ºF (15ºC). Butter an 8 x 4 inch loaf pan, dust the inside of the pan with flour and tap out the excess. Line the bottom with parchment paper, butter the paper, dust the paper with flour, and tap out the excess. Or spray the loaf pan with non-stick spray if you have one. Set aside.
Whisk together flour, baking powder, baking soda, and salt in a medium bowl.
Place sugar and Meyer lemon zest in a food processor and pulse 30 seconds.
Beat butter and lemon-sugar in a large mixer bowl at medium speed until light and fluffy and then beat in egg and vanilla.
Combine yogurt and buttermilk in a small bowl.
Reduce speed to low and add half of flour mixture, beating just to combine. Add yogurt mixture, then finish with remaining flour mixture.
Pour batter into prepared pan and smooth top. Give the pan several sharp taps on the counter to bring up any air bubbles that may be trapped in the batter. Bake for 60 minutes, or until a toothpick inserted in the center comes out clean.
Cool in pan on a wire rack for 10 minutes; carefully remove cake from pan and cool completely on wire rack.
To prepare glaze, sift powder sugar in a bowl and add Meyer lemon zest.
Add Meyer lemon juice and whisk all together.
Drizzle glaze over cooled cake and let set before serving.
Keep the leftovers in an airtight container and store in the refrigerator for up to 3 days.