Preheat oven to 350. With a gluten-free cooking spray, coat two 9x5 loaf pans.
With a hand or stand mixer, beat butter until light and fluffy. Add honey and lemon zest and beat once again combined and fluffy. Add one egg at a time, blending completely.
In a separate bowl, mix starches and rice flour with the baking soda, baking powder, ground flaxseed, and salt.
Blending on low, add in a third of the dry ingredients. Add in sour cream and half of the remaining dry ingredients. Finally, add the lemon juice and the remainder of the dry ingredients until blended thoroughly.
Divide the batter between the two loaf pans (or bake one at a time if you only have one like me!) and bake for 45-50 minutes or until an inserted toothpick comes out clean. Tip - You may need to tent a piece of foil over the top of your loaf pan in the last 5 to 10 minutes if the perimeter is browning and the center still has times to go.
Cool the pound cakes in loaf pans for about an hour and then invert onto a foil or parchment lined baking sheet.
To make Lemon Syrup, heat honey and lemon juice over low until combined. Using a skewer or toothpick, poke holes in top of inverted pound cake and brush syrup over top. If you are adding Lemon Glaze as well, allow syrup to soak in first.
To make Lemon Glaze, whisk powdered sugar and lemon juice together until smooth and thick. Pour over pound cake(s) and let sit for about an hour.