Step 1

Preheat the oven to 375ºF. Make filling: Melt 3 Tbsp. butter in a 10 1/2-inch cast-iron skillet over medium-high heat. Add peaches and cook, stirring occasionally, until they begin to soften, 3 to 4 minutes. Add 1/4 cup sugar, cinnamon and a pinch of salt and cook, stirring frequently, until sugar has dissolved and peaches are soft and most of their liquid has evaporated, 3 to 5 minutes longer. Remove skillet from heat.

Step 2

Combine flour, baking powder, 1/2 tsp. salt, remaining 1/2 cup sugar and remaining 13 Tbsp. butter in a food processor; pulse until mixture resembles coarse meal. With motor running, add milk and vanilla, and process just until a rough dough forms.

Step 3

Drop spoonfuls of topping over warm peaches and sprinkle with almonds, if desired. Bake until topping is golden, 30 to 35 minutes. Let stand 15 minutes. Serve warm, topped with a scoop of vanilla ice cream, if desired.