01 -
Heat your oven to 350°F (175°C) and coat an 8x8-inch pan with nonstick spray.
02 -
In a big bowl, toss together the oats, flour, baking soda, and salt.
03 -
Mix in both the granulated sugar and brown sugar.
04 -
Pour in the melted butter and vanilla, then stir until everything is evenly blended.
05 -
Firmly press half of the mix into the bottom of your prepared pan.
06 -
Pop it in the oven for 15 minutes.
07 -
As the base cooks, whisk together the lemon zest, egg yolks, lemon juice, and condensed milk.
08 -
After the crust is baked, pour the lemon filling on top. Sprinkle the rest of the crumble mix evenly across the surface.
09 -
Bake again for about 20–22 minutes, until the top gets a light golden color.
10 -
Set the pan aside to cool fully, then refrigerate until firm.