Ask a Vegan Baker

The sugar in my sugar cookies don't dissolve so the cookies turn out grainy. I creamed the vegan butter and sugar together for a long time and the dough is grainy as well. I don't really know what to do about it. FYI- they are for regular sugar cookies (not the cut out kind). Could it be that I use organic sugar which is more coarse than refined white sugar? Here's the recipe:
1 Tbsp ground flax + 3 Tbsp water
1 1/2 cups all purpose flour
1 tsp baking soda
1/2 tsp salt
1/4 cup Earth Balance butter
1/4 cup vegetable shortening
3/4 cup white granulated sugar
1 tsp vanilla extract
- I combine the ground flax and water and let it rest for 10 minutes. In the meantime, I would cream the butter and shortening together for about 3 minutes, then added the sugar and creamed that together for a very long time, then added the flax mixture and vanilla until incorporated, then stir in the dry ingredients. The dough turned out grainy with sugar. How could I fix this?