Gluten Free Cinnamon Streusel Coffee Cake YUM!!! This was the most fabulous thing ever! Like some of the others, I made substitutions - 3-4 tablespoons of agave in place of the sugar, added 2 tablespoons of sour cream and a tablespoon of canola oil. So good! For those new to gluten free baking - adding a little sour cream seems to really offset the gluten free flour twang and makes it taste so much like the "real" thing. I add it to all my baking. One other tip - if the batter tastes gritty (I know you aren't supposed to taste it, but please - I have my entire life) - the cake will be gritty / won't hold together as well. I usually add water until I get the right consistency in the batter. Baking doesn't make it more moist. In this recipe, with the changes above (sour cream and agave in place of sugar) I probably used about what the recipe calls for in terms of the water. GREAT! Make it - you'll love!