Preheat oven to 350F.
Get out and measure all of your ingredients.
To a large bowl add the cored and quartered strawberries with cornstarch and toss.
Add the sugar and lemon zest, toss again.
Set aside while building the topping.
In a large bowl combine the flour, oats, brown sugar, cinnamon, nutmeg, and salt.
Use fingers to blend together.
Pour in melted butter and vanilla extract. Use a spoon to combine, making sure all of the topping mixture is wet.
Pour the strawberry mixture into a 2 quart casserole dish. Cover with topping.
Spread out until top is covered.
Bake for 40 minutes until top is golden brown and strawberries are bubbling. Remove from oven and allow to sit for 10 minutes.
Serve with vanilla ice cream or whipped cream and enjoy every bite!