Preheat the oven to 425 degrees. Note that you will turn the heat down to 350 degrees after the first 15 minutes of baking.. Grease the bottom and sides of a 9 x 13 or 9 x 9 baking pan or casserole dish.
Rinse, hull, and cut the strawberries into a small dice. Lay them on paper towels to dry and absorb excess moisture while you work on the batter.
In a small bowl, combine the 2 cups of flour, baking powder and salt. Set aside.
In a large bowl, cream the sugar and butter with a hand mixer. Add the eggs and continue to mix. Add the ½ & ½ and vanilla.
When all is combined well, add the flour, baking powder, and salt mixture. Mix at a low speed until all of the dry ingredients are mixed in, then scrape the bowl and continue mixing for another minute until it is smooth & creamy.
Pour the batter into the bottom of the baking pan and smooth it out from edge to edge with a spatula.
Scatter half of the strawberries evenly on top, reserving the other half for serving.
In a small bowl, combine the gluten free flour and sugar. Gradually add melted butter until crumbles begin to form. Sprinkle evenly on top of the strawberries.
Bake for 15 minutes at 425 degrees. Then turn the heat down to 350 degrees. Continue baking for 15-20 minutes until the center is puffed slightly in the middle and no longer soft & squishy.
For the Glaze: While stirring with a spoon, add the water or milk, gradually to the powdered sugar, until it begins to dissolve into a thick glaze. Work out lumps by continuing to stir.
Remove from the oven and let cool for 10-15 minutes before drizzling the glaze on top and serving with more fresh berries. Or put the fresh berries on top of the cake and drizzle with the glaze. Serve with coffee, tea, whipped cream, or ice cream.