Preheat oven to 350 degrees. Line a 15x10 cake pan with parchment paper, set aside.
Start by adding your eggs to a bowl or stand mixer. Beat eggs for 3 minutes on medium-high speed until frothy and pale.
Gradually add sugar and beat for 4-5 minutes longer, until it nearly triples in volume and is very thick, pale and fluffy. Mix in salt.
Drop the mixer speed to low speed and slowly add in the salt, milk, oil, vinegar and vanilla and continue until well incorporated.
Sift flour and baking powder into a medium bowl and whisk to blend evenly.
Fold the dry ingredients into the whipped egg mixture ¼ cup at a time just until combined without over-mixing.
Spread batter evenly into a parchment lined 15x10 pan in a thin layer. Bake for 12-15 minutes at 350 degrees until it springs back when pressed gently. Transfer pan to a wire rack and let cool for 3 minutes so it is easier to handle.
Dust top of cake evenly with powdered sugar. Run a knife along the edges of the pan to release the cake, then invert it onto a clean kitchen towel or another large piece of parchment paper.
Gently peel off the top layer of parchment. While the cake is still warm, gently roll it into a log starting from the short side and incorporating the kitchen towel or parchment as you are rolling. Let the cake cool completely in this rolled shape.
Unroll the cake, spread the dulce de leche over it leaving about ½ inch border and then gently roll up the cake again. Transfer to a baking tray and refrigerate for 3 hours before serving.