Cook the sweet potatoes

• Peel the sweet potatoes and cut them into 1-inch chunks, keeping them fairly consistent in size.
• Put them in a pot, cover with water and season generously with salt.
• Bring to a boil, then reduce to a simmer and cook until tender; pierce one with a knife to check.

Make the streusel

• Combine equal parts flour and brown sugar with the salt and the chopped pecans.
• Add the melted butter and mix until it looks like wet, clumpy sand.

Drain and mash

• Drain the sweet potatoes in a colander.
• Mash them really well until fairly lump free.

Finish the filling

• Add the melted butter, brown sugar, milk, vanilla extract and eggs to the mashed sweet potatoes.
• Stir until smooth and well combined.

Assemble

• Transfer the filling to a buttered baking dish and smooth the top.
• Sprinkle the streusel evenly all over the top.

Bake

• Bake until golden and the streusel is crunchy.