Combine 1/4 cup buttermilk and baking soda in a small bowl. Set aside until step 5.
In a stand mixer, cream together the butter and sugar.
Add 1 egg and 1 egg yolk. (Save the egg white for brushing over the rolled dough. Place the egg white in a covered container in the fridge for overnight.) Then add the salt, vanilla and 1/4 cup buttermilk. Mix well.
Add 1 1/2 cups of flour and the baking powder. Blend until combined.
Add the buttermilk/baking soda mixture and the last 1 1/2 cups of flour. Mix until the flour is completely incorporated. The dough will be very sticky. It's important to do the next step of refrigerating the dough so that it firms up.
Wrap the cookie dough in plastic wrap and gently press it into a disc. Be sure it is wrapped tightly and refrigerate the dough overnight.
The next day, lightly flour a pastry mat.
Roll the dough to a rectangle about 11x19”.
Brush the cookie dough with the egg white.
Sprinkle the dough with the cinnamon and sugar.
Starting at the long end, roll up the sugar cookie dough carefully jelly roll style. Make sure the roll is tight.
Use thread or floss to cut the dough in ½” thick slices.
Bake at 350º for 9-10 minutes. Do NOT overbake or they will be dry. The cookies should puff up slightly when done, but not be brown.
Allow the cookies to cool on a wire rack.
For the glaze option:
Place the powdered sugar in a medium-size bowl.
Add the vanilla extract and heavy cream. Whisk until smooth.
Dollop the icing on top of each cookie while the cookies are still warm.
Allow the glaze to melt slightly, then use a pastry brush to cover the cookie completely. Some of the glaze may run off and that’s ok.
Move the cookies while they are still warm to a wire rack to cool completely. If you wait, the powdered sugar frosting may crack slightly when moving.
This option doesn’t look as pretty, but the glaze melts in slightly and makes the cookies taste amazing.
For the cream cheese frosting option:
In a medium size bowl, mix the butter and cream cheese together until smooth and creamy.
Add the powdered sugar and vanilla. Mix well until all of the sugar is mixed in, scraping the sides of the bowl as needed.
When the cookies are completely cool, use a knife to spread the frosting over the cookies. Or you can use Wilton tip 1A to pipe a pretty dollop of frosting on top.
Store the ingredients in an airtight container at room temperature.
Notes
The calories shown are based on the recipe making about 26 glazed cookies, with 1 serving being 1 glazed cookie. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information. The information in the nutrition box are calculated through a program and there is room for error. If you need an accurate count, I recommend running the ingredients through your favorite nutrition calculator.**