Preheat your oven to 350°F. Grease an 8x8 baking pan and line with parchment paper, leaving a 2" overhang on both sides.
In a large bowl, mix together the flour, rolled oats, sugars, baking soda, and baking powder.
Melt the butter in a microwave safe dish and then stir in the vanilla. Pour this over the flour/oat mixture and use a spatula to fold everything together until combined.
Press this oat cookie dough in an even layer into the base of your baking dish. Bake for 15 minutes.
Pull the crust out and let it cool for 10 minutes. In the meantime, whisk the sweetened condensed milk, egg yolks, lemon zest, lemon juice, and pinch of salt together until blended.
Pour the lemon mixture over the crust and use a spoon to spread it into an even layer. Bake for an additional 20-15 minutes, or until edges are brown and filling is set.
Let the bars cool completely, then transfer to the fridge for chill for at least an hour.
Once you're ready to serve, toss the strawberries with the brown sugar. Let them rest for 10 minutes so that the sugar dissolves, then spoon the strawberries onto the bars. Slice in the 16 squares. Enjoy!