Preheat oven to 300 degrees F (150 degrees C). Line a jelly roll pan with parchment paper.
Beat butter in a large bowl with and electric mixer until fluffy. Add confectioner's sugar, cinnamon hearts, vanilla extract, cinnamon oil, baking soda, and baking powder; stir using a wooden spoon. Add flour 1 cup at a time, mixing by hand until dough sticks together.
Push dough onto the prepared pan, flattening the corners to make an even layer.
Bake in the preheated oven until corners start to turn a light brown, 35 to 40 minutes. Cool on a rack for 10 minutes; lift shortbread out of the pan by holding onto the parchment paper. Cut into 2-inch squares.