Line two baking sheets with parchment paper and heat oven to 350°F.
Sift together flour, cinnamon, baking soda and salt. Set aside.
Place ½ cup butter, granulated sugar and ¼ cup of brown sugar in a stand mixer bowl fitted with a paddle attachment and beat until light in colour.
Add in egg yolk, applesauce, light corn syrup and vanilla and beat to combine.
Using a sturdy spatula or wooden spoon, fold in flour mixture until just combined. Dough may have some flour streaking. (Do not over mix.)
Divide dough in half and wrap in waxed paper and refrigerate for 30 minutes.
Place remaining 1 tbsp of cinnamon and ½ cup of brown sugar in a bowl and whisk to combine.
Divide cinnamon and brown sugar mixture in two; one for each portion of halved dough. Set aside.
Remove one wrapped dough. Dough will sticky so place it between two large pieces of wax paper and roll out dough to 1/4 inch thickness.
Using a pastry brush spread 1 ½ tbsp of softened butter on dough.
Sprinkle half of the cinnamon and sugar mixture on top and gently press it into dough. Roll up dough, beginning with long side.
Place roll seam side down on plastic wrap and cover tightly.
Repeat this once more with remaining dough and 1½ tbsp of butter, along with remaining cinnamon and brown sugar mixture.
Place both rolls of dough back in refrigerator for 30-45 minutes.
Remove chilled roll and cut into ½ inch slices.
Bake at 350°F for about 10 minutes or until lightly browned.
Let cool for 2 minutes on baking sheet, then remove to wire racks to cool completely.
