14 Ounces Sweetened Condensed Milk - 1 or 2 cans, depending on taste (see above)
1 Cup Butter, Softened
2 Cups Packed Light Brown Sugar
2 Large Eggs (Room Temperature)
2 Tsp Vanilla
2 1/2 Cups Flour
2 Tsp Baking Powder
1 Tsp Salt
1/4 Cup Sugar
1 Tbl Ground Cinnamon
Remove label(s) from sweetened condensed milk. Place on its side in an extra large pot and fill with water. You need to cover it with at least two inches of water. Put on stove and bring to a simmer. Simmer for 2.5 hours. Check every thirty minutes and add more boiling water as necessary to keep at least one inch of water above can. At end of cooking time, use tongs to place on a cooling rack. DO NOT try and open before completely cool.
Heat oven to 350.
Line a 9 X 13 plan with parchment paper - make sure it overhangs the two long edges.
In a large bowl, cream together butter and sugar. Beat in eggs and vanilla. Add flour, baking powder and salt until combined. Spread in bottom of prepared pan.
In a small bowl, combine Sugar and Cinnamon. Sprinkle 2.5 tablespoons over the batter in the pan. Bake 30 minutes (edges should be light brown. Cool completely on a wire rack.
When cool, open sweetened condensed milk and spread evenly over top of cookie crust. Sprinkle with remaining sugar/cinnamon mixture.
Refrigerate at least one hour. Remove from pan and cut. Keep leftovers in refrigerator.