diff --git a/crates/e2e-test-utils/src/node.rs b/crates/e2e-test-utils/src/node.rs
index 4dd1ae63e1..90877a5809 100644
--- a/crates/e2e-test-utils/src/node.rs
+++ b/crates/e2e-test-utils/src/node.rs
@@ -2,11 +2,11 @@ use crate::{network::NetworkTestContext, payload::PayloadTestContext, rpc::RpcTe
 use alloy_consensus::{transaction::TxHashRef, BlockHeader};
 use alloy_eips::BlockId;
 use alloy_primitives::{BlockHash, BlockNumber, Bytes, Sealable, B256};
-use alloy_rpc_types_engine::ForkchoiceState;
+use alloy_rpc_types_engine::{ExecutionPayloadEnvelopeV5, ForkchoiceState};
 use alloy_rpc_types_eth::BlockNumberOrTag;
 use eyre::Ok;
 use futures_util::Future;
-use jsonrpsee::http_client::HttpClient;
+use jsonrpsee::{core::client::ClientT, http_client::HttpClient};
 use reth_chainspec::EthereumHardforks;
 use reth_network_api::test_utils::PeersHandleProvider;
 use reth_node_api::{
@@ -20,6 +20,7 @@ use reth_provider::{
     BlockReader, BlockReaderIdExt, CanonStateNotificationStream, CanonStateSubscriptions,
     HeaderProvider, StageCheckpointReader,
 };
+use reth_rpc_api::TestingBuildBlockRequestV1;
 use reth_rpc_builder::auth::AuthServerHandle;
 use reth_rpc_eth_api::helpers::{EthApiSpec, EthTransactions, TraceExt};
 use reth_stages_types::StageId;
@@ -319,4 +320,20 @@ where
 
         Ok(crate::testsuite::NodeClient::new_with_beacon_engine(rpc, auth, url, beacon_handle))
     }
+
+    /// Calls the `testing_buildBlockV1` RPC on this node.
+    ///
+    /// This endpoint builds a block using the provided parent, payload attributes, and
+    /// transactions. Requires the `Testing` RPC module to be enabled.
+    pub async fn testing_build_block_v1(
+        &self,
+        request: TestingBuildBlockRequestV1,
+    ) -> eyre::Result<ExecutionPayloadEnvelopeV5> {
+        let client =
+            self.rpc_client().ok_or_else(|| eyre::eyre!("HTTP RPC client not available"))?;
+
+        let res: ExecutionPayloadEnvelopeV5 =
+            client.request("testing_buildBlockV1", [request]).await?;
+        eyre::Ok(res)
+    }
 }
diff --git a/crates/ethereum/node/tests/e2e/eth.rs b/crates/ethereum/node/tests/e2e/eth.rs
index 1865890482..2fcfa26802 100644
--- a/crates/ethereum/node/tests/e2e/eth.rs
+++ b/crates/ethereum/node/tests/e2e/eth.rs
@@ -1,6 +1,10 @@
 use crate::utils::eth_payload_attributes;
+use alloy_eips::eip7685::RequestsOrHash;
 use alloy_genesis::Genesis;
-use reth_chainspec::{ChainSpecBuilder, MAINNET};
+use alloy_primitives::{Address, B256};
+use alloy_rpc_types_engine::{PayloadAttributes, PayloadStatusEnum};
+use jsonrpsee_core::client::ClientT;
+use reth_chainspec::{ChainSpecBuilder, EthChainSpec, MAINNET};
 use reth_e2e_test_utils::{
     node::NodeTestContext, setup, transaction::TransactionTestContext, wallet::Wallet,
 };
@@ -8,6 +12,7 @@ use reth_node_builder::{NodeBuilder, NodeHandle};
 use reth_node_core::{args::RpcServerArgs, node_config::NodeConfig};
 use reth_node_ethereum::EthereumNode;
 use reth_provider::BlockNumReader;
+use reth_rpc_api::TestingBuildBlockRequestV1;
 use reth_tasks::TaskManager;
 use std::sync::Arc;
 
@@ -180,3 +185,74 @@ async fn test_engine_graceful_shutdown() -> eyre::Result<()> {
 
     Ok(())
 }
+
+#[tokio::test]
+async fn test_testing_build_block_v1_osaka() -> eyre::Result<()> {
+    reth_tracing::init_test_tracing();
+    let tasks = TaskManager::current();
+    let exec = tasks.executor();
+
+    let genesis: Genesis = serde_json::from_str(include_str!("../assets/genesis.json")).unwrap();
+    let chain_spec = Arc::new(
+        ChainSpecBuilder::default().chain(MAINNET.chain).genesis(genesis).osaka_activated().build(),
+    );
+    let genesis_hash = chain_spec.genesis_hash();
+
+    let node_config =
+        NodeConfig::test().with_chain(chain_spec.clone()).with_unused_ports().with_rpc(
+            RpcServerArgs::default()
+                .with_unused_ports()
+                .with_http()
+                .with_http_api(reth_rpc_server_types::RpcModuleSelection::All),
+        );
+
+    let NodeHandle { node, node_exit_future: _ } = NodeBuilder::new(node_config)
+        .testing_node(exec)
+        .node(EthereumNode::default())
+        .launch()
+        .await?;
+
+    let node = NodeTestContext::new(node, eth_payload_attributes).await?;
+
+    let wallet = Wallet::default();
+    let raw_tx = TransactionTestContext::transfer_tx_bytes(1, wallet.inner).await;
+
+    let payload_attributes = PayloadAttributes {
+        timestamp: chain_spec.genesis().timestamp + 1,
+        prev_randao: B256::ZERO,
+        suggested_fee_recipient: Address::ZERO,
+        withdrawals: Some(vec![]),
+        parent_beacon_block_root: Some(B256::ZERO),
+    };
+
+    let request = TestingBuildBlockRequestV1 {
+        parent_block_hash: genesis_hash,
+        payload_attributes,
+        transactions: vec![raw_tx],
+        extra_data: None,
+    };
+
+    let envelope = node.testing_build_block_v1(request).await?;
+
+    let engine_client = node.auth_server_handle().http_client();
+    let payload = envelope.execution_payload.clone();
+    let block_hash = payload.payload_inner.payload_inner.block_hash;
+
+    let versioned_hashes: Vec<B256> = Vec::new();
+    let parent_beacon_block_root = B256::ZERO;
+    let execution_requests = RequestsOrHash::Requests(envelope.execution_requests);
+
+    let status: alloy_rpc_types_engine::PayloadStatus = engine_client
+        .request(
+            "engine_newPayloadV4",
+            (payload, versioned_hashes, parent_beacon_block_root, execution_requests),
+        )
+        .await?;
+    assert_eq!(status.status, PayloadStatusEnum::Valid);
+
+    node.update_forkchoice(genesis_hash, block_hash).await?;
+
+    node.wait_block(1, block_hash, false).await?;
+
+    Ok(())
+}