1 1/2 cups all-purpose flour (plus more for dusting the cake pan)
1 tablespoon baking powder
4 large eggs (separated)
1 cup sugar
1/2 cup whole milk
1 14-ounce can sweetened condensed milk
1 12-ounce can evaporated milk
1 1/2 cup Baileys Irish Cream Liqueur
Whipped topping:
1 ½ cups heavy cream
1/3 cup powdered sugar
Fresh strawberries
Preheat the oven to 350 degrees F. Grease and flour a 9-inch square pan or a 9×13 pan lined with parchment paper.
Mix the flour and baking powder in a medium bowl. Set aside.
In a large mixing bowl, using an electric mixer with the whisk attachment, whip the egg whites until frothy, about 2 minutes. With the mixer running, gradually add the sugar and beat to stiff peaks (about 5 minutes). Beat in the yolks, 1 at a time, blending well after each addition. Next, add the flour mixture in 3 additions, alternating with the milk in 2 additions.
Pour the batter into the prepared pan and bake until a tester inserted into the center comes out clean, about 22-25 minutes. Cool the cake slightly, about 10 minutes, then invert onto a deep platter or remove parchment from cake pan and return cake to pan.
Pierce the top of the cake all over with a fork or toothpick. In a medium bowl, mix the sweetened condensed milk, evaporated milk and baileys Irish cream. Pour the mixture over the cake while warm. Cover and refrigerate until cold, about 4 hours or overnight.
Combine the heavy cream and powdered sugar in a medium bowl. Turn the electric mixer to medium and beat the cream on medium until soft peaks form (about 3 minutes). Increase the speed to medium-high and beat for 1-2 more minutes until fluffy. Spread the whipped cream on top of the refrigerated cake and serve with fresh strawberries.
This cake will last up to 3 days in the refrigerator.