1 teaspoon ground cinnamon, plus more for sprinkling
One 14-ounce can sweetened condensed milk
Sliced fresh strawberries, whipped cream (see recipe here), and mint leaves, for serving (optional)
Preheat the oven to 350°F. Lightly grease a 9x13-inch baking pan with butter.
In a medium bowl, mix together the flour, baking powder, and salt. Set aside.
In a stand mixer fitted with the paddle attachment, beat the eggs and sugar on medium-high speed until light and fluffy and the color is lightened, 6 to 7 minutes. Slowly add 2 teaspoons of the vanilla and mix until just combined.
With the mixer on low speed, add half of the flour mixture, then the milk, finishing with the remaining flour mixture, mixing well after each addition.
Pour the batter into the prepared pan and bake until a tester inserted into the center comes out clean, 23 to 28 minutes. Let the cake cool completely, approximately 1 hour.
Meanwhile, in a medium saucepan, whisk together the cream, evaporated milk, and cinnamon. Bring to a boil over medium heat, then reduce the heat and simmer for 2 minutes, stirring occasionally, until completely combined and smooth. Set aside for 5 to 8 minutes to let the flavors meld.
Whisk the sweetened condensed milk and the remaining 1 teaspoon vanilla into the cream mixture.
Using a fork, poke holes in the top of the cooled cake. Pour the cream mixture over the cake. Cover with plastic wrap and refrigerate for at least 2 hours or overnight.
Slice and sprinkle each serving with cinnamon. Serve with sliced strawberries, whipped cream, and fresh mint leaves, if desired.
Store covered in the refrigerator for up to 3 days.