Follow these steps to bring a piece of my kitchen into yours:

1. Preheat your oven to 350°F (175°C) and line a 9×13 inch baking pan with parchment paper.
2. Cream the butter and sugar: In a large mixing bowl, beat together the softened butter and granulated sugar until light and fluffy, about 3-4 minutes. This step reminds me of the countless times I watched my grandmother work her magic with just a whisk and bowl.
3. Add the dry ingredients: Mix in the flour, baking powder, and salt, combining until you have a crumbly dough. Stir in the vanilla extract.
4. Press the dough: Take about two-thirds of the dough and press it evenly into the prepared baking pan to form the base.
5. Prepare the topping: In a separate bowl, combine the remaining dough with the oats, brown sugar, honey, and chopped pistachios. This will form a delicious, crumbly topping.
6. Add the blackberries: Spread the blackberries evenly over the dough in the baking pan. If there’s one thing I’ve learned, it’s that the imperfect scattering of berries adds to the charm and flavor.
7. Top the bars: Sprinkle the pistachio-oat mixture over the blackberries, pressing down gently to ensure it sticks.
8. Bake: Place the pan in the preheated oven and bake for 25-30 minutes, or until the top is golden brown and the edges are bubbling with berry goodness.
9. Cool and slice: Allow the bars to cool completely in the pan before slicing them into squares. This waiting period is always the hardest part for my family!