Preheat the oven to 350F. Line a square 8-inch metal baking pan with a piece of parchment paper or foil so it comes up and over two sides by about an inch (you’ll use it to lift the finished bars out of the pan). Set aside.
In a medium bowl, stir together the flour, oats, brown sugar, baking soda, and salt.
Add the eggs, butter, vanilla, lemon juice, and lemon zest. Use clean hands or a fork to gently mix the dough together until it’s uniform and crumbly. Set aside 3/4 cup of the mixture.
Add the remaining mixture to the bottom of the prepared pan, pressing evenly to cover the bottom and to fill in any holes.
Stir together the strawberries and preserves.
Evenly spread the strawberry mixture over top. Crumble the remaining dough mixture over top to cover evenly and press it down slightly. Bake for 35-40 minutes or until lightly browned.
Remove from the oven and let cool on a wire rack until room temperature.
Use the parchment paper to lift out of the pan and slice into bars carefully using a serrated knife.