Step 1: Preheat and Prepare
Preheat your oven to 350°F (175°C). Generously grease an 8×8-inch baking dish with butter or cooking spray, making sure to coat the bottom and all sides thoroughly. The lemon and honey can make things a bit sticky, so don’t skimp on the greasing.

Step 2: Zest and Juice Lemons
Before juicing your lemons, use a microplane or fine grater to zest them. You need 2 tablespoons of zest total. Then cut and juice the lemons to get 1/3 cup of fresh juice. Set both aside. Pro tip: Always zest before juicing—it’s much easier!

Step 3: Mix Dry Ingredients
In a medium bowl, whisk together the oats, baking powder, salt, poppy seeds (if using), and lemon zest. Mixing the zest with the dry ingredients helps distribute that bright lemon flavor evenly throughout. Set aside.

Step 4: Combine Wet Ingredients
In a large bowl, whisk together the milk, eggs, honey, Greek yogurt, lemon juice, melted butter, and vanilla extract. Whisk vigorously for about 30 seconds until the mixture is completely smooth, slightly frothy, and the Greek yogurt is fully incorporated with no lumps.

Step 5: Combine Wet and Dry
Pour the dry oat mixture into the bowl with the wet ingredients. Stir gently with a rubber spatula until just combined—don’t overmix. The mixture should be pourable but thick, similar to thick pancake batter. It might look a bit curdled from the lemon juice reacting with the dairy—this is completely normal and fine!

Step 6: Transfer to Baking Dish
Pour the oatmeal mixture into your prepared baking dish. Use a spatula to spread it evenly into all corners and smooth the top. Tap the dish gently on the counter a couple times to release any air bubbles.

Step 7: Bake
Bake in the preheated oven for 35-40 minutes, or until the edges are golden brown, the top is set and lightly golden, and a toothpick inserted in the center comes out with just a few moist crumbs (not wet batter). The top should look slightly puffed and have a beautiful golden color reminiscent of toasted meringue.

Step 8: Cool and Serve
Remove from the oven and let rest for 10 minutes before cutting. This crucial resting time allows the oatmeal to set properly so it slices cleanly without being too liquidy. Cut into 6-8 squares and serve warm with your favorite toppings. A sprinkle of fresh lemon zest on top makes it extra beautiful!