My adaptations in red:
For the cream cheese filling:
One 8-oz. pkg cream cheese, not softened
1/3 cup sugar
1 large egg, at room temp.
2 tbs. plain flour
For the brownies:
1 1/4 cups plain flour
1 tsp. baking powder
1/4 tsp. salt
1 cup (2 sticks) butter, softened (2 sticks is a pack of butter in the UK) 4 ounces unsweetened chocolate (I used Menier dark chocolate) 2 cups sugar
3 large eggs, at room temperature
2 tbs. whole milk
1 1/2 tsp. vanilla extract
3/4 cup coarsely chopped toasted pecans
2/3 cup chopped Heath bars, or any chocolate-covered toffee bars (I used Curly Wurlies, put them in the freezer to harden before chopping them. Three bars made 2/3 cupful)
Preheat oven to 325 degrees F. Grease and flour a 13x9-inch baking pan.
Firstly, make the cream cheese topping: In a medium-size bowl, beat the cream cheese with the sugar until smooth. Add the egg and flour and beat well. Set aside.
Now for the rest of the brownie mixture. In a small bowl, combine the flour, baking powder, and salt. Set aside.
In a medium-size saucepan over low heat, melt the butter with the chocolate, stirring occasionally, until smooth. Remove from the heat, transfer to a large bowl, and allow to cool for about 5 minutes until lukewarm.
Stir in the sugar. Add the eggs, milk, and vanilla and beat well. Add the dry ingredients and mix thoroughly.
Stir in half of the pecans and half of the Curly Wurlies. Reserve 1/2 cup of the brownie batter.
Spread the rest of the batter evenly in the prepared pan.
Drop the cream cheese mixture by tablespoonfuls over the batter. Next, drop the reserved brownie batter by teaspoonfuls in between the cream cheese filling.
Using a small knife, swirl the two batters together, forming a decorative pattern.
Sprinkle the remaining pecans and Curly Wurlies over the top, and using a spatula, gently press into the batter.
Bake for 40-55 minutes, or until a cake tester inserted in the centre of the pan comes out with moist crumbs attached. Do not over bake. Allow to cool overnight before cutting and serving.
Note: To toast the pecans, place on a baking sheet in a 350 degree F oven for 5-10 minutes, or until lightly browned and fragrant. Be careful to not let them burn!