For the crumb topping: In a medium bowl, mix together the brown sugar, flour, almonds and salt. Add the butter and stir to combine until the mixture is evenly moistened and crumbs form. Set aside.
For the cake: Preheat the oven to 350 degrees F. Spray a 9-by-13-inch baking dish with nonstick cooking spray. Set aside.
In a large bowl, combine the butter, brown sugar and granulated sugar. Using a handheld mixer on medium speed, beat the butter and sugars together until light and fluffy, about 2 minutes. Add the sour cream, vanilla, salt and eggs. Beat on medium to combine. Add 1 1/2 cups of the flour, the baking powder and baking soda. Mix again until smooth, about 1 minute. Add the milk and mix again until smooth. Add the remaining 2 cups of flour and the lemon zest and fold with a rubber spatula, being careful not to overmix. Pour the batter into the prepared baking dish and sprinkle evenly with the strawberries and basil.
Top with the crumb topping and bake until a toothpick inserted in the center comes out clean, 45 to 50 minutes.