Lemon poppy seed pie with coffee

Ingredients:

Pie

• 110g unsalted butter at room temperature, plus extra for greasing the pan
• 2 cups premium flour + extra for dusting
• 1 teaspoon baking powder
• 0.5 tsp of soda
• 2 tsp poppy seeds
• 0.5 tsp coarse salt
• 1 cup granulated sugar
• 4 tsp finely grated lemon zest
• 2 large eggs
• 1 tsp vanilla extract
• 1 cup sour cream
• Powdered sugar, for dusting

Topping

• 3/4 cup premium flour
• 2/3 cup light brown sugar
• 0.5 cups oatmeal
• 2 tsp poppy seeds
• 0.5 tsp freshly grated nutmeg
• 1/4 teaspoon coarse salt
• 6 tablespoons chilled unsalted butter, cut into small pieces

Preparation:

1. Preheat oven to 350°F (175°C). Lightly grease a 9-inch (22cm) square baking pan; dust with flour and shake out any excess.
2. Pie:
   
   In a medium bowl, combine the flour, baking powder, baking soda, poppy seeds, and salt. In a large bowl, beat the butter, sugar, and lemon zest with a mixer on medium-high speed until light and fluffy, 3-4 minutes. Add the eggs one at a time, beating well after each addition, then beat in the vanilla extract. Reduce the mixer speed to low and beat in the flour mixture in two additions, alternating with the sour cream, scraping down the sides of the bowl as needed. Pour the dough into the prepared baking dish.
3. Topping:
   
   In a bowl, combine flour, brown sugar, oats, poppy seeds, nutmeg, and salt; work in butter with your fingers until the mixture resembles coarse grains.
4. Sprinkle the topping over the dough. Bake, rotating the pan halfway through, until a toothpick inserted into the center comes out clean, 50 minutes to 1 hour. Transfer the cake to a wire rack and let cool completely. Dust with powdered sugar just before serving.