Preheat oven to 375° Fahrenheit. Pull out a 10 inch oven safe skillet or your favorite deep pie dish and set to the side.
Make the rose sugar. To do this, break up the rosebuds or petals with a mortar and pestle or spice grinder. They don't need to be too finely ground, just in small pieces. Add the rose bits to 1 cup sugar and toss or mix to combine.
Now make the filling. In a large bowl, combine the strawberries, 1/4 tsp salt, 1 tbsp lemon juice, 3/4 cup rose sugar, 1 tsp rosewater, and 2 tsp corn starch. Toss to coat, then transfer to your skillet or pie dish.
Make the streusel. Add the flour, rolled oats, butter, 1/4 tsp salt, and 1/4 cup rose sugar to a medium sized bowl. Work it together with clean hands. You'll want to form a crumbly dough. Crumble this dough over the filling.
Bake for 40-50 minutes until the filling is bubbly and the top is golden brown. Let cool for about 20 minutes before serving (warm and with vanilla ice cream is my favorite way to eat this) and enjoy!